Saving freshwater from salts Cañedo-Argüelles, M.; Hawkins, C. P.; Kefford, B. J. ...
Science (American Association for the Advancement of Science),
02/2016, Volume:
351, Issue:
6276
Journal Article
Peer reviewed
Ion-specific standards are needed to protect biodiversity
Many human activities—like agriculture and resource extraction—are increasing the total concentration of dissolved inorganic salts (i.e., ...salinity) in freshwaters. Increasing salinity can have adverse effects on human health (
1
); increase the costs of water treatment for human consumption; and damage infrastructure e.g., amounting to $700 million per year in the Border Rivers catchment, Australia (
2
). It can also reduce freshwater biodiversity (
3
); alter ecosystem functions (
4
); and affect economic well-being by altering ecosystem goods and services (e.g., fisheries collapse). Yet water-quality legislation and regulations that target salinity typically focus on drinking water and irrigation water, which does not automatically protect biodiversity. For example, specific electrical conductivities (a proxy for salinity) of 2 mS/cm can be acceptable for drinking and irrigation but could extirpate many freshwater insect species (
3
). We argue that salinity standards for specific ions and ion mixtures, not just for total salinity, should be developed and legally enforced to protect freshwater life and ecosystem services. We identify barriers to setting such standards and recommend management guidelines.
We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to 2009 September, for a total of 76 GRBs, and present ...an additional three pre-Swift GRBs not included in an earlier sample. Furthermore, we publish 840 additional new photometry data points on a total of 42 GRB afterglows, including large data sets for GRBs 050319, 050408, 050802, 050820A, 050922C, 060418, 080413A, and 080810. We analyzed the light curves of all GRBs in the sample and derived spectral energy distributions for the sample with the best data quality, allowing us to estimate the host-galaxy extinction. We transformed the afterglow light curves into an extinction-corrected z = 1 system and compared their luminosities with a sample of pre-Swift afterglows. The results of a former study, which showed that GRB afterglows clustered and exhibited a bimodal distribution in luminosity space, are weakened by the larger sample. We found that the luminosity distribution of the two afterglow samples (Swift-era and pre-Swift) is very similar, and that a subsample for which we were not able to estimate the extinction, which is fainter than the main sample, can be explained by assuming a moderate amount of line-of-sight host extinction. We derived bolometric isotropic energies for all GRBs in our sample, and found only a tentative correlation between the prompt energy release and the optical afterglow luminosity at 1 day after the GRB in the z = 1 system. A comparative study of the optical luminosities of GRB afterglows with echelle spectra (which show a high number of foreground absorbing systems) and those without, reveals no indication that the former are statistically significantly more luminous. Furthermore, we propose the existence of an upper ceiling on afterglow luminosities and study the luminosity distribution at early times, which was not accessible before the advent of the Swift satellite. Most GRBs feature afterglows that are dominated by the forward shock from early times on. Finally, we present the first indications of a class of long GRBs, which form a bridge between the typical high-luminosity, high-redshift events and nearby low-luminosity events (which are also associated with spectroscopic supernovae) in terms of energetics and observed redshift distribution, indicating a continuous distribution overall.
In this paper we study the class of laterally complete commutative unital regular algebras
A
over arbitrary fields. We introduce a notion of passport Γ(
X
) for a faithful regular laterally complete
...A
modules
X
, which consist of uniquely defined partition of unity in the Boolean algebra of all idempotents in
A
and of the set of pairwise different cardinal numbers. We prove that
A
-modules
X
and
Y
are isomorphic if and only if Γ(
X
) = Γ(
Y
). Further we study Banach
A
-modules in the case
A
=
C
∞
(
Q
) or
A
=
C
∞
(
Q
)+
i ·C
∞
(
Q
). We establish the equivalence of all norms in a finite-dimensional (respectively,
σ
-finite-dimensional)
A
-module and prove an
A
-version of Riesz Theorem, which gives the criterion of a finite-dimensionality (respectively,
σ
-finite-dimensionality) of a Banach
A
-module.
A simple photo-voltaic tracking system Karimov, Kh.S.; Saqib, M.A.; Akhter, P. ...
Solar energy materials and solar cells,
05/2005, Volume:
87, Issue:
1
Journal Article, Conference Proceeding
Peer reviewed
This paper describes a simple photo-voltaic (PV) tracking system which has been designed and manufactured using a pyramidal stand as a base. A rotating unit consisting of two pairs of modules fixed ...at an angle of 170° between them was installed at the upper edge of the stand. The four modules and a DC motor were connected to a bridge circuit making the system sensitive to solar tracking. The PV tracker has a DC–DC (24/2
V) converter, DC–AC (24/220
V) inverter and a battery. The modules are able to provide a maximum power of ∼100
W, which feeds the converter, inverter and DC motor. Wind resistance of the tracker is quite low. The total area of the four modules is 1.26
m
2. The inclination angle between the modules and the horizontal plane is adjustable (34°±11°) and the tracking angle is 120°. The system can track solar motion with an error of ±10°. The designed PV tracking system, with modules fixed at an angle of 170° to feed the load as well as the DC motor, exhibited it to be an efficient energy-conversion system. The fabricated system offers low wind resistance. The cost analysis data revealed that the proposed design was very economical and cost effective.
Let A be a laterally complete commutative regular algebra and X be a laterally complete A-module. In this paper we introduce a notion of homogeneous and strictly homogeneous A-modules. It is proved ...that any homogeneous A-module is strictly homogeneous A-module, if the Boolean algebra of all idempotents in A is multi-σ-finite.
WATER. Saving freshwater from salts Cañedo-Argüelles, M; Hawkins, C P; Kefford, B J ...
Science (American Association for the Advancement of Science),
2016-Feb-26, 20160226, 2016-02-26, Volume:
351, Issue:
6276
Journal Article
Purpose
Imaging glioma biology holds great promise to unravel the complex nature of these tumors. Besides well-established imaging techniques such O-(2-18Ffluoroethyl)-
l
-tyrosine (FET)-PET and ...dynamic susceptibility contrast (DSC) perfusion imaging, amide proton transfer–weighted (APTw) imaging has emerged as a promising novel MR technique. In this study, we aimed to better understand the relation between these imaging biomarkers and how well they capture cellularity and vascularity in newly diagnosed gliomas.
Methods
Preoperative MRI and FET-PET data of 46 patients (31 glioblastoma and 15 lower-grade glioma) were segmented into contrast-enhancing and FLAIR-hyperintense areas. Using established cutoffs, we calculated hot-spot volumes (HSV) and their spatial overlap. We further investigated APTw and CBV values in FET-HSV. In a subset of 10 glioblastoma patients, we compared cellularity and vascularization in 34 stereotactically targeted biopsies with imaging.
Results
In glioblastomas, the largest HSV was found for APTw, followed by PET and CBV (
p
< 0.05). In lower-grade gliomas, APTw–HSV was clearly lower than in glioblastomas. The spatial overlap of HSV was highest between APTw and FET in both tumor entities and regions. APTw correlated significantly with cellularity, similar to FET, while the association with vascularity was more pronounced in CBV and FET.
Conclusions
We found a relevant spatial overlap in glioblastomas between hotspots of APTw and FET both in contrast-enhancing and FLAIR-hyperintense tumor. As suggested by earlier studies, APTw was lower in lower-grade gliomas compared with glioblastomas. APTw meaningfully contributes to biological imaging of gliomas.
This research compromises of an innovative investigation based on semitransparent vertical cylinder-shaped thermoelectric cells (TEC’s). The temperature gradient was generated by light illumination. ...Cells with antimony doped bismuth telluride (Bi2Te3) were fabricated and its electric parameters were measured with different modifications to obtain the optimum design for maximum power efficiency. The thermoelectric material was filled in the semi-transparent plastic cylindrical tube with external and internal diameters and length of 6 mm, 5 mm and 20 mm. The open circuit voltage (VOC) and short circuit current (ISC) dependences with respect to averaged temperature and gradient of temperature were measured. These variations of temperature were controlled by varying the intensity of light. The fabricated semitransparent thermoelectric cells have 25% transparency. The investigation of thermoelectric properties of p-Bi2Te3 showed that increasing the average temperature from 34 to 60 °C, the increment in the current and voltage of the thermoelectric cells is 4.45 and 3.3 times. However, after modifications increased the current 10.1 and 8.9 times in case of water reservoir as a coolant, 16.5 and 14 times with large metallic top electrode, 19.3 and 19.5 times when all modifications added together, respectively. Overall optimum results were obtained with the least number of glasses, maximum load pressure, larger metallic electrode receiver, water reservoir as a coolant to get most temperature gradient. Potentially the semitransparent thermoelectric cells can be built and used to fabricate special windows which produce, electric power, allow to illuminate inside house directly by solar light without conversion to the energy and to heat water.
•Researched the semitransparent photo-thermo-electric cell’s effect of p-type bismuth telluride alloy.•After optimization of TE cells its open-circuit voltage and short-circuit current was measured.•Semitransparent TEC’s produce electric power as well as allow light to illuminate through cell and heat water.
In this study, we investigate signature flips within the framework of cosmological models featuring a time-varying vacuum energy term
Λ
(
t
)
. Specifically, we consider the power-law form of
Λ
=
α
H
...n
, where
α
and
n
are constants. To constrain the model parameters, we use the MCMC technique, allowing for effective exploration of the model’s parameters. We apply this approach to analyze 31 points of observational Hubble Data (OHD), 1048 points from the Pantheon data, and additional CMB data. We consider three scenarios: when
n
is a free parameter (Case I), when
n
=
0
(Case II), and when
n
=
1
(Case III). In our analysis across all three cases, we observe that our model portrays the universe’s evolution from a matter-dominated decelerated epoch to an accelerated epoch, as indicated by the corresponding deceleration parameter. In addition, we investigate the physical behavior of total energy density, total EoS parameter, and jerk parameter. Our findings consistently indicate that all cosmological parameters predict an accelerated expansion phase of the universe for all three cases (
q
0
<
0
,
ω
0
<
-
1
3
,
j
0
>
0
). Furthermore, our analysis reveals that the
Om
(
z
) diagnostics for Cases I and III align with the quintessence region, while Case II corresponds to the
Λ
CDM model.
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