1,240 research outputs found
Assessment of Specific Yield and Storage Capacity of Groundwater using Borehole Log
The study aimed at evaluating the specific yield and storage capacity of groundwater in Chapai Nawabganj District of Bangladesh using borehole log data. The boring log samples from different layers were collected from each Upazila (administrative area) of the District. The specific yield of each Upazila was determined by the Cooper-Jacob method using Math lab software and storage of groundwater was then ascertained by a mathematical formula. The specific yield of the five Upazilas was determined and the values were found around 10 (%) which indicates good permeability of the areas, except Bholahat Upazila. The results illustrate that Nachole Upazila has a large storage volume, i.e., 49,305 Hec-m, but the other Upazilas have a storage capacity between 8000 to 18000 Hec-m. The storage capacity of the five Upazilas followed the order: Nachole>Nawabganj>Shibganj>Gomastapur> Bholahat. The highest number of DTWs at Nachole Upazila extracted 8848 Hec-m indicating excessive extraction concerning sustainable water management. A well-planned water resource management would have to be taken to achieve sustainable use of groundwater for irrigation aiming to achieve food security as well as an ecologically friendly environment. Keywords: Borehole, groundwater, storage, specific yield, storage capacity DOI: 10.7176/JEES/10-8-02 Publication date:August 31st 202
Observation of Motion Dependent Nonlinear Dispersion with Narrow Linewidth Atoms in an Optical Cavity
As an alternative to state-of-the-art laser frequency stabilisation using
ultra-stable cavities, it has been proposed to exploit the non-linear effects
from coupling of atoms with a narrow transition to an optical cavity. Here we
have constructed such a system and observed non-linear phase shifts of a narrow
optical line by strong coupling of a sample of strontium-88 atoms to an optical
cavity. The sample temperature of a few mK provides a domain where the Doppler
energy scale is several orders of magnitude larger than the narrow linewidth of
the optical transition. This makes the system sensitive to velocity dependent
multi-photon scattering events (Dopplerons) that affect the cavity field
transmission and phase. By varying the number of atoms and the intra-cavity
power we systematically study this non-linear phase signature which displays
roughly the same features as for much lower temperature samples. This
demonstration in a relatively simple system opens new possibilities for
alternative routes to laser stabilization at the sub 100 mHz level and
superradiant laser sources involving narrow line atoms. The understanding of
relevant motional effects obtained here has direct implications for other
atomic clocks when used in relation with ultranarrow clock transitions.Comment: 9 pages (including 4 pages of Supplemental Information), 6 figures.
Updated to correspond to the published versio
Sediment Denitrification Potential in the Elizabeth River, Virginia
Sediment denitrification potential from two sites in the Elizabeth River estuary was studied over a nine-month period using the acetylene blockage method. Rates of microbial processes in this environment are of interest because of the high concentration of toxics present in some parts of the system. Highest rates were found in the highly polluted Southern Branch of the Elizabeth River with nitrate amended sediment ranging from 2-262 nmol N20/h per 20ml of sediment and exhibiting maximal rates during spring and fall. Rates in the Main Stem of the Elizabeth River were lower, with less than 1-85 nmol N2O/h/20ml in nitrate amended sediment, and maxima in late fall. Unamended sediment from the Southern Branch denitrified in spring (2-131 nmol N2O/h/20ml) and fall (1-124 nmol N2O/h/20ml) only. Main Stem unamended sediment denitrified ony minimally in the spring. Sediment denitrification potential was independent of temperature and dissolved oxygen in the water column. Comparison of phytoplankton abundance values and potential denitrification rates suggest that denitrification potential may be stimulated by phytoplankton bloom senescence. Comparison to other published studies shows sediment denitrification potential in the Elizabeth River to be within the range of values reported for other environments
The Effect of Group Rational Emotive Behavior Restructuring on Mental Health of Parents of Exceptional Children
AbstractThe purpose of this research is to study the effectiveness of group Rational Emotional Behavioral restructuring on mental health of parents of exceptional children. Pre-Test Post-Test experimental design with control group was used. 60 parents were chosen randomly and divided into experimental and control groups. Munsh Mental Health Self-Evaluation Scale was used. The experimental group received 10 sessions of 90minutes of group Rational Emotional Behavioral restructuring once weekly. The intervention contained teaching REBT basics, rational and irrational beliefs and also their impact on emotions and behavior, group discussions for exploring their beliefs, feelings and behaviors in everyday life in particular toward their exceptional children. The results indicated the group Rational Emotional Behavioral restructuring had a significant effect on increasing the level of mental health parents of exceptional children
Multiple stochastic pathways in forced peptide-lipid membrane detachment
We have used high resolution AFM based dynamic force spectroscopy to investigate peptide-lipid membrane interactions by measuring the detachment (last-rupture) force distribution, P(F), and the corresponding force dependent rupture rate, k(F), for two different peptides and lipid bilayers. The measured quantities, which differed considerably for different peptides, lipid-membranes, AFM tips (prepared under identical conditions), and retraction speeds of the AFM cantilever, could not be described in terms of the standard theory, according to which detachment occurs along a single pathway, corresponding to a diffusive escape process across a free energy barrier. In particular, the prominent retraction speed dependence of k(F) was a clear indication that peptide-lipid membrane dissociation occurs stochastically along several detachment pathways. Thereby, we have formulated a general theoretical approach for describing P(F) and k(F), by assuming that peptide detachment from lipid membranes occurs, with certain probability, along a few dominant diffusive pathways. This new method was validated through a consistent interpretation of the experimental data. Furthermore, we have found that for moderate retraction speeds at intermediate force values, k(F) exhibits catch-bond behavior (i.e. decreasing detachment rate with increasing force). According to the proposed model this behavior is due to the stochastic mixing of individual detachment pathways which do not convert or cross during rupture. To our knowledge, such catch-bond mechanism has not been proposed and demonstrated before for a peptide-lipid interaction
Ratio of shear viscosity to entropy density in multifragmentation of Au + Au
The ratio of the shear viscosity () to entropy density () for the
intermediate energy heavy-ion collisions has been calculated by using the
Green-Kubo method in the framework of the quantum molecular dynamics model. The
theoretical curve of as a function of the incident energy for the
head-on Au+Au collisions displays that a minimum region of has been
approached at higher incident energies, where the minimum value is
about 7 times Kovtun-Son- Starinets (KSS) bound (1/4). We argue that the
onset of minimum region at higher incident energies corresponds to the
nuclear liquid gas phase transition in nuclear multifragmentation.Comment: 6 pages, 8 figure
The Bengal Water Machine: Quantified freshwater capture in Bangladesh
Global food security depends on the sustainability of irrigated agriculture. Rising groundwater withdrawals from seasonally humid, alluvial plains across tropical Asia have enabled dry-season rice cultivation. This groundwater pumpage increases available subsurface storage that under favorable conditions amplifies groundwater replenishment during the subsequent monsoon. We empirically quantified this nature-based solution to seasonal freshwater storage capture described as the "Bengal Water Machine," revealing its potential and limitations. On the basis of a million piezometric observations from 465 monitoring wells, we show that the collective operation of ~16 million smallholder farmers in the Bengal Basin of Bangladesh from 1988 to 2018 has induced cumulative freshwater capture that volumetrically (75 to 90 cubic kilometers) is equivalent to twice the reservoir capacity of the Three Gorges Dam
The cursed duet today: Tuberculosis and HIV-coinfection
The tuberculosis (TB) and HIV syndemic continues to rage and are a major public health concern worldwide. This deadly association raises complexity and represent a significant barrier towards TB elimination. TB continues to be the leading cause of death amongst HIV-infected people. This paper reports the challenges that lay ahead and outlines some of the current and future strategies that may be able to address this co-epidemic efficiently. Improved diagnostics, cheaper and more effective drugs, shorter treatment regimens for both drug-sensitive and drug-resistant TB are discussed. Also, special topics on drug interactions, TB-IRIS and TB relapse are also described. Notwithstanding the defeats and meagre investments, diagnosis and management of the two diseases have seen significant and unexpected improvements of late. On the HIV side, expansion of ART coverage, development of new updated guidelines aimed at the universal treatment of those infected, and the increasing availability of newer, more efficacious and less toxic drugs are an essential element to controlling the two epidemics. On the TB side, diagnosis of MDR-TB is becoming easier and faster thanks to the new PCR-based technologies, new anti-TB drugs active against both sensitive and resistant strains (i.e. bedaquiline and delamanid) have been developed and a few more are in the pipeline, new regimens (cheaper, shorter and/or more effective) have been introduced (such as the “Bangladesh regimen”) or are being tested for MDR-TB and drug-sensitive-TB. However, still more resources will be required to implement an integrated approach, install new diagnostic tests, and develop simpler and shorter treatment regimens
How important are supermarkets for the diets of the urban poor in Africa?
Many developing countries are undergoing a profound transformation of food systems and retail environments. Especially in urban areas, a rapid growth of supermarkets is observed, which can affect consumer food choices and diets. Supermarkets may improve access to diverse foods at affordable prices, but may also encourage a switch from unprocessed to highly-processed and energy-dense foods that contribute to obesity. However, the use of supermarkets is positively correlated with income. That supermarkets already play an important role for the diets of many urban consumers does not necessarily mean that this is also true for the poorest population segments that are of particular interest for development policy. This article analyzes the diets and food purchase patterns of poor urban consumers in Kenya and Uganda. Representative data were collected from households in the slums of Nairobi and Kampala. The data show that the majority of these households are undernourished. They buy most food items in unprocessed form from various traditional retail outlets, including mom-and-pop shops, local markets, and kiosks. Relatively few sample households buy any of their food in supermarkets. Supermarkets account for only 3% and 0.4% of all food expenditures of slum dwellers in Nairobi and Kampala, respectively. Reasons for the low supermarket use of these poor households are discussed. The findings suggest that a focus on the modern retail sector alone will not suffice to ensure food and nutrition security for all
Therapeutic approaches to pediatric pseudotumor cerebri: new insights from literature data
The pseudotumor cerebri syndrome (PTCS), also known as idiopathic intracranial hypertension (IIH), is characterized by signs and symptoms of increased intracranial pressure such as headache and cranial nerve palsies, in the absence of any space-occupying mass. This condition commonly affects overweight women of childbearing age, even if it is also frequent in men and children. Children with PTCS may present with atypical signs and symptoms, with a different prognosis compared to adults. However, the treatment is the same for both children and adults, even if there are no strict treatment guidelines in regards. All treatment strategies in children are based on retrospective studies and none has been evaluated in prospective or randomized controlled trial studies. This review focuses on literature data on PTCS treatment in children
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