bluuebunny/crossref_metadata_2025 huggingface dataset:
Apparent environmental synergism drives the dynamics of Amazonian forest fragments
Authors: Laurance William F. , Andrade Ana S. , Magrach Ainhoa , Camargo José L. C. , Campbell Mason , Fearnside Philip M. , Edwards Will , Valsko Jefferson J. , Lovejoy Thomas E. , Laurance Susan G.
Published: May 2014

Many contemporary ecosystems are likely to be affected by multiple environmental drivers, complicating efforts to predict future changes in those ecosystems. We studied long‐term changes (1980–2012) in forest dynamics and liana (woody vine) abundance and biomass in fragmented and intact forests of the central Amazon. We did so by contrasting trends in 33 permanent 1‐ha plots near forest edges (plot center <100 m from the nearest edge) with those in 36 1‐ha plots in intact‐forest interiors (150–3300 m from nearest edge). In fragmented and edge‐affected forests, rates of tree (≥10 cm diameter at breast height) mortality and recruitment were often sharply elevated, especially in the first 10–15 years after fragmentation. Lianas (≥2 cm stem diameter) also increased markedly in abundance (mean ± SD = 1.78 ± 1.23% per yr) and biomass (1.30 ± 1.39% per yr) over time, especially in plots with high edge‐related tree mortality. However, plots in undisturbed forest interiors, which were originally established as experimental controls, also experienced long‐term changes. In these plots, tree mortality and recruitment rose significantly over time, as did liana abundance (1.00 ± 0.88% per yr) and biomass (0.32 ± 1.37% per yr). These changes were smaller in magnitude than those in fragments but were nonetheless concerted in nature and highly statistically significant. The causes of these changes in forest interiors are unknown, but are broadly consistent with those expected from rising atmospheric CO2 or regional climate drivers that influence forest dynamics. Hence, the dynamics of Amazonian forest fragments cannot be understood simply as a consequence of forest fragmentation. Rather, the changes we observed appear to arise from an interaction of fragmentation with one or more global‐ or regional‐scale drivers affecting forest dynamics. Both sets of phenomena are evidently increasing forest dynamics and liana abundances in fragmented forests, changes that could reduce carbon storage and alter many aspects of forest ecology.
The Effect of In-Line Infusion Filtering on In-Line Pressure Monitoring in an Experimental Infusion System for Newborns
Authors: Jonckers Tinneke , Berger Ingrid , Kuijten Twan , Meijer Eduard , Andriessen Peter
Published: May 2014

Aim: To study the effect of in-line filtering on in-line pressure measurement in a simulated infusion system.

Methods: The experimental setup consisted of a syringe pump, syringe, intravenous (IV) line, and extension line. For aqueous fluids, a 0.2-μm infusion filter was used, and for lipid emulsions, a 1.2-μm filter. Infusion speed varied from 0.5 to 10.0 mL/h. First, the effect of clamping the extension line was studied on reaching alarm threshold. Second, the effect of aqueous and lipid fluids was evaluated on in-line pressure measurements.

Results: In-line placement of an infusion filter did not prolong the time to alarm threshold after occlusion. During 24 hours of monitoring, lipid emulsions and all-in-one admixture only caused a moderate increase in in-line pressure.

Conclusion: Placement of an infusion filter does not have a significant effect on the in-line pressure monitoring and has no adverse effect on detecting pressure-related complications of IV administration.
Preventing Admission Hypothermia in Very Low Birth Weight Neonates
Authors: Fawcett Kristin
Published: May 2014

Neonatal hypothermia, temperature <36.5°C, is a major contributor to neonatal mortality and morbidity. Hypothermia of preterm infants remains a challenge in the NICU for many reasons. Preterm very low birth weight (VLBW) infants, those infants born <1,500 g, are prone to very rapid heat losses through mechanisms of convection, evaporation, conduction, and radiation. This article reviews current research to reduce and prevent mortality and morbidity from hypothermia in preterm VLBW infants by implementing interventions in the delivery room to minimize heat loss and maintain core body temperatures.
Who Is Billy Reuben? Health Literacy and Patient Education
Authors: Pilcher Jobeth , Flanders Sonya
Published: May 2014

The issue of health literacy is focused on whether health consumers understand and are able to apply the information provided to them. In the neonatal setting, limited parent and caregiver health literacy can result in increased stress and poor compliance with instructions. Health literacy and patient education go hand in hand. This article includes an overview of health literacy and how it applies to the neonatal setting. Information is provided to assist with assessing for health literacy. Hints and resources are also provided for improving patient and family education.
Understanding Triglyceride Levels Related to Intravenous Fat Administration
Authors: Weaver Karen , Nash Patricia L.
Published: May 2014

Lipid is an essential macronutrient in parenteral nutrition (PN) support. Intravenous (IV) lipid provides essential fatty acids and a concentrated calorie source. Preterm infants are at risk for essential fatty deficiency early in life. Lipid administration is associated with some risks, and there are guidelines for administration to minimize complications. Lipid emulsions in the United States are derived from soybean oil. Outside of the United States, lipid emulsions made from fish oil or combinations of fish, soybean, olive, and medium-chain triglycerides (MCTs) are under investigation for improved tolerance, lower plasma lipid levels, and improved fatty acid profiles, all of which are considered beneficial. Triglyceride levels are an important measurement to assess patient tolerance.
Intervention for Mothers Who Have Experienced Childbirth-Related Trauma and Posttraumatic Stress Disorder
Authors: Kendall-Tackett Kathleen
Published: May 2014

Lactation consultants may be one of the first healthcare providers who see mothers following a difficult birth. As such, they can be key sources of support and information for mothers at this critical time. Several aspects of the International Board Certified Lactation Consultant’s
(IBCLC) scope of practice can fit within trauma-informed care, including helping mothers identify possible trauma symptoms and posttraumatic stress disorder (PTSD), and addressing breastfeeding issues that may be sequelae of a traumatic birth. IBCLCs can inform mothers about their treatment
options and refer them to additional sources of support. This article describes breastfeeding issues that might arise in the wake of a traumatic birth and summarizes evidence-based treatment options for PTSD so that IBCLCs can share this information with mothers.
Does Kinesio Elastic Therapeutic Taping Decrease Breast Engorgement in Postpartum Women?
Authors: Brown Donna , Langdon Claire
Published: May 2014

Breast engorgement is a common problem in the early postpartum period. The purpose of this study was to determine the effectiveness of Kinesio Elastic Therapeutic Taping® (K-ETT), used to increase lymphatic drainage or decrease fluid in congested areas, in treating breast engorgement
in postpartum women. Thirty-four healthy mothers who delivered healthy babies over a 4-week period in a large community hospital participated, with one breast taped and the other remaining untaped. Two subjective measures, self-reported pain and self-rated engorgement, and one objective measure,
firmness by durometer measured by the researchers, were taken at baseline and throughout the study period. Engorgement was defined as exceeding a threshold in at least two of the three measures. Overall, 65% of mothers experienced engorgement. There was no difference in the incidence of engorgement,
comparing the taped to the untaped breast by paired analysis. Future work in this area should include development and testing of valid and reliable measures of engorgement, followed by testing of interventions using a rigorous protocol to provide evidence for practice change.
Experiences of Australian School Staff in Addressing Student Cannabis Use
Authors: Gates Peter J. , Norberg Melissa M. , Dillon Paul , Manocha Ramesh
Published: May 2014

Cannabis is the most frequently used illicit drug by Australian secondary school students yet there is scant research investigating school staff responses to student cannabis use. As such, this study surveyed 1,692 school staff who attended Generation Next seminars throughout Australia. The self-complete survey identified that the majority of school staff had discussed cannabis use at least once in the past year, although teachers were less likely to report having cannabis-related discussions compared to other school staff. Staff drug education training was consistently associated with an increased prevalence of cannabis-related discussion and assistance. These findings highlight a need for drug education among school staff and particularly among teachers.
Assess the Impact of an Online Tobacco Prevention Training Program on Teachers and Their Students
Authors: Chen W. William , Sheu Jiunn-Jye , Weng Chung-Bang
Published: May 2014

School-based tobacco prevention programs have been proven effective in reducing tobacco use. This evaluation aimed to assess the impact of an online tobacco prevention teacher training program on teachers and their students in Florida schools. A total of 344 teachers, including 72 K-3 grade teachers, 44 4th-5th grade teachers, and 228 6th-12th grade teachers completed the online training program and 323 (93.9%) were followed up to assess impacts on their 6,490 students. Results suggested that the online tobacco prevention education program for teachers was effective with high satisfaction and the impact on students was significant in improving knowledge and attitude about tobacco use and in increasing the proportion of 6–12th grade students who decided not to use tobacco. The evaluation study recommended the online education program be continued and expanded in the future.
Cross-National Study on Factors That Influence Parents' Knowledge about Their Children's Alcohol Use
Authors: Fernandez-Hermida Jose-Ramon , Calafat Amador , Becoña Elisardo , Secades-Villa Roberto , Juan Montse , Sumnall Harry
Published: May 2014

Previous research has shown that parents underestimate their children's substance use. The aim of the present work was to analyze parental estimation of their children's use of alcohol in five countries from northern, central, and southern Europe, and to explore the variables that influenced this perceptual bias. The sample comprised 1181 parent-children dyads living in Sweden, Slovenia, the Czech Republic, Spain, and Portugal. In accordance with the findings of previous studies, we found high parental underestimation of substance use, which was greater for more frequent alcohol use or the use of illegal drugs. This underestimation appears to be subject to some degree of sociocultural influence, and is also influenced by the severity of the children's use.
Faculty Perceptions of Their Roles in Alcohol Education/Prevention
Authors: Walter Katherine Ott , Paulo Jonathan R. , Polacek Georgia N. L. J.
Published: May 2014

Alcohol use among college students continues to be a major public health threat to our nation. The purpose of this study was to explore faculty perceptions of their roles and responsibilities in alcohol education and prevention. The researchers adapted the Core Faculty and Staff Environmental Alcohol and Other Drug Survey to include only questions regarding alcohol and created additional questions concerning Friday classes. The survey was sent to all faculty members ( N = 1,712). Completed surveys were collected from 122 faculty members (7.1%). The majority (95%) agreed that institutions of higher education should be involved in alcohol awareness efforts. Fewer (76%) agreed that they could positively affect students' alcohol consumption. Responses from open-ended questions revealed areas where faculty perceived they could have the most impact. Recommendations include implementing the Institute of Medicine strategies on campuses and incorporating faculty in these alcohol education and prevention strategies.
Drugged Driving: Increased Traffic Risks Involving Licit and Illicit Substances
Authors: Pilkinton Melinda W. , Robertson Angela , McCluskey D. Lee
Published: May 2014

Driving under the influence of drugs poses risks for traffic safety. Most research attention has been focused on the most prevalent drugs of abuse, such as alcohol, illegal drugs, and prescription drugs with high abuse potential. The objectives of this study were to determine the types of drugs used by convicted DUI offenders on the day of their arrest, prevalence of poly-substance use, and offender characteristics associated with different drug use patterns. Data were collected from 6,339 individuals enrolled in the court-mandated Mississippi Alcohol Safety Education Program. After alcohol, cannabis was the most frequently used substance, followed by sedative medications and prescription analgesics. Among poly-substance users, 78.4% reported combining alcohol with other drugs. Findings could be used to inform public education campaigns, law enforcement training, and highway safety policies about the prevalence of combining alcohol with other drugs, as well as how poly-substance use further impairs traffic-related risks.
Inhibition of growth and induction of apoptosis in human lung cancer cells by Br-oxph
Authors: Koleva Vanya , Dragoeva Asya , Draganov Marian , Melendezalafort Laura , Rosato Antonio , Uzunov Nikolay , Enchev Dobromir
Published: May 2014

The study was aimed at evaluating apoptotic potential of Br-oxph
(4-bromoN,N-diethyl-5,5-dimethyl-2,5-dihydro-1,2-oxaphosphol-2-amine 2-oxide)
in vitro. The dose response effect of Br-oxph (dose range 1-3 mg/ml, for 48
h) on SK-MES-1 cells viability was determined by means of WST-1 cell
proliferation assay. The half maximal inhibitory concentration (??50) value
was determined - 1.8 mg/ml. The ability of the compound tested to induce
apoptosis was tested by ELISA to detect cellular DNA fragmentation. We
provided a quantitative assessment of the apoptotic potential of Br-oxph in
human lung carcinoma cells at concentrations corresponding to ??50 and 2???50
for 3 hours. Treatment with 2???50 significantly increased the amount of
cytoplasmic DNA-fragments. Results obtained from the present study confirm
that Br-oxph target the cancerous cells towards apoptosis.
Molecular characterization and genetic diversity analysis of different rice cultivars by microsatellite markers
Authors: Allhgholipour Mehrzad , Farshdfar Ezatollah , Rabiei Babak
Published: May 2014

A total of 52 rice SSR markers well distributed on 12 chromosomes were used
to characterize and assess the genetic diversity among ninety four rice
genotypes. The total number of polymorphic alleles was 361 alleles with the
average of 5.86 alleles per SSR locus. The study revealed that some markers
such as RM276 and RM5642 on chromosome 6 and RM14 and RM1 on chromosome 1
have more than 9 observed alleles compared to other primers like RM16, RM207,
RM208 and RM317 with 3-4 alleles. The highest and lowest PIC values were
observed for primers RM276 (0.892 and RM208 (0.423) respectively. Using
Shannon?s diversity index, a mean genetic diversity of 1.641 was obtained
from the analysis, indicating a high level of genetic variation among these
cultivars. Cluster analysis using the complete linkage method based on
jaccard similarity coefficient revealed that all genotypes were classified to
nine clusters at genetic similarity level of 0.010.75, which contained 12,
16, 2, 18, 3, 6, 16, 10 and 11 varieties, respectively. Results of
discriminant analysis showed that the nine cluster groups were confirmed at
high levels of correct percent (96.8) and revealed true differences among
these clusters. As a final result from this study, we selected eight
cultivars from different cluster including Daylamani, Tarom mohali (landrace
rice cultivars), RI1843046, Back cross line, RI184472, RI184421 (promising
cultivars), Line 23 and IR50 (IRRI lines) as parents. All of the selected
cultivars will be arranged in complete diallel design to obtain combining
abilities, gene effects and heterosis for each important morphology and
physico-chemical characters.
Compatibility and verdure of seedling for autochtonous peer in the region of north Montenegro
Authors: Sebek Gordana , Kovacevic Visnja
Published: May 2014

The study was conducted in three successive years to examine the
compatibility and verdure in nursery trees of autochthonous peer cultivars
grafted on Quince MA and wild peer seedlings (Pyrus communis L) during the
first year after bud grafting. The aim of this paper is to determine
compatibility and verdure of autochthonous peer seedling sorts (Pecanka,
Jerebasma, Lubenicarka, Sinka, Tursijaca and Jarac) with the Quince MA and
wild peer seedlings (Pyrus communis L). The severity of incompatibility
varies between varieties but is always more severe with Quince MC than Quince
MA. The incompatibility expresses itself in several ways. Firstly a poor
?bud? or ?graft? take in the nursery will be evident, secondly even if
growing successfully in the nursery very often when ?lifted? breakages
(brittle unions) occur between rootstock and scion and thirdly ?delayed?
incompatibility where again the union between rootstock and scion breaks
suddenly in later years, this is unpredictable and can often happen when
there is a heavy crop load assisted by strong autumnal winds. The production
of seedling material of autochthonous sorts with vegetative rootstocks Quince
MA will be enormous contribution for even partially saving of fruit genofond
that is the unity product of our ecological environment and autochthonous
biocenosis.
A new experimental method to prevent paraffin - wax formation on the crude oil wells: A field case study in Libya
Authors: Elhaddad Elnori , Bahadori Alireza , Abdel-Raouf Manar , Elkatatny Salaheldin
Published: May 2014

Wax formation and deposition is one of the most common problems in oil
producing wells. This problem occurs as a result of the reduction of the
produced fluid temperature below the wax appearance temperature (range
between 46?C and 50?C) and the pour point temperature (range between 42?C and
44?C). In this study, two new methods for preventing wax formation were
implemented on three oil wells in Libya, where the surface temperature is,
normally, 29?C. In the first method, the gas was injected at a pressure of
83.3 bar and a temperature of 65?C (greater than the pour point temperature)
during the gas-lift operation. In the second method, wax inhibitors
(Trichloroethylene-xylene (TEX), Ethylene copolymers, and Comb polymers) were
injected down the casings together with the gas. Field observations confirmed
that by applying these techniques, the production string was kept clean and
no wax was formed. The obtained results show that the wax formation could be
prevented by both methods.
Calculation and optimization of the copper (II) sulphate monohydrate from copper (II) sulphate pentahydrate production process in a fluidized bed dryer
Authors: Kaludjerovic-Radoicic Tatjana , Radovic Ivona , Ivanovic Marija , Rajic Nevenka , Grbavcic Zeljko
Published: May 2014

In this paper the process of the copper (II) sulphate monohydrate from copper
(II) sulphate pentahydrate (also known as a Blue vitriol or Bluestone)
production was analyzed. Copper (II) sulphate pentahydrate is one of the most
important copper salts which has been known since the ancient Egyptians. In
the nineteenth century its application as a fungicide was discovered which
provoked wide industrial production. Molecule of the copper (II) sulphate
pentahydrate is a crystalohydrate with five water molecules linked by
chemical bonds to a molecule of the copper (II) sulphate. Copper (II)
sulphate exists as a series of compounds that differ in their degree of
hydratation. The anhydrous form is a pale green or gray-white powder, whereas
the pentahydrate (CuSO4?5H2O), the most commonly encountered salt, is bright
blue. In order to obtain copper (II) sulphate monohydrate from copper (II)
sulphate pentahydrate four water molecules need to be removed. To determine
the optimum temperature and time required for the removal of four water
molecules from a molecule of pentahydrate in this work thermogravimetric
(TGA) analysis was performed. Thermogravimetric (TGA) analysis - dehydration
of copper (II) sulphate pentahydrate is done using simultaneous TG-DSC
thermal analyzer DTG-Q600 SDT from TA Instruments. Analyzes was carried out
for two type of samples, the sample containing particles of the average
diameter equal to 0.17 mm and the particles of the average diameter 0.5 mm.
In addition, fluidization and drying curve was determined using a
semi-industrial fluidization column. On top, the industrial fluidization
column aimed to produce 300 tones per month of copper (II) sulphate
monohydrate was designed. Material and energy calculations were performed
using software packages Simprosys 3.0 and SuperPro Designer 5.1. Simprosys
3.0 is a software package designed for the modeling and simulation of a
drying process as well as for 20 different unit operations. SuperPro Designer
5.1 facilitates modeling, evaluation and optimization of different industrial
processes including drying. These softwares were applied for the calculation
of the air flow rate, heat exchange and for the scoping of a dryer.
Susceptibility of modern relay protection: Will protection from cyber attacks help?
Authors: Gurevich Vladimir
Published: May 2014

Modern trends in relay protection (RP) based on the substitution of
electromechanical protection relays (EMPR) by digital protective relays
(DPR) have resulted in the emergence of an absolutely new problem, which was
not known before. This problem is the possibility of an intentional remote
destructive impact (IRDI) on relay protection in order to put it out of
action or make it perform functions that have nothing to do with the current
operational mode of protected electric equipment. Traditional and well-known
methods ensuring information safety cannot fully prevent unauthorized
actions of RP. The article describes a new way for the problem solution.
The numerical method of inverse Laplace transform for calculation of overvoltages in power transformers and test results
Authors: Mikulovic Jovan , Sekara Tomislav
Published: May 2014

A methodology for calculation of overvoltages in transformer windings, based
on a numerical method of inverse Laplace transform, is presented.
Mathematical model of transformer windings is described by partial
differential equations corresponding to distributed parameters electrical
circuits. The procedure of calculating overvoltages is applied to windings
having either isolated neutral point, or grounded neutral point, or neutral
point grounded through impedance. A comparative analysis of the calculation
results obtained by the proposed numerical method and by analytical method of
calculation of overvoltages in transformer windings is presented. The results
computed by the proposed method and measured voltage distributions, when a
voltage surge is applied to a three-phase 30 kVA power transformer, are
compared.
Mousetracking visitors to evaluate efficacy of web site design
Authors: Jevremovic Aleksandar , Adamovic Sasa , Veinovic Mladen
Published: May 2014

Objective assessment of website design is a complex task whose results are
valuable for improving efficiency. Some of the commonly used methods, such as
A/B testing, are relatively simple to implement but generally give only a
rough summary of results. Eyetracking is one of the most efficient methods,
but requires the use of expensive equipment and is not generally applicable
to the web environment. Mousetracking is a far cheaper and implementable
alternative to eyetracking and some studies indicate a high degree of
correlation between the results of these two methods. This paper presents the
architecture of a system for mousetracking, and the results of its use in a
particular website.
Towards an improved energy efficiency of the interior permanent magnet synchronous motor drives
Authors: Gecic Marko , Marcetic Darko , Vasic Veran , Krcmar Igor , Matic Petar
Published: May 2014

This paper investigates the possibility of energy efficiency increase in the
drives with high speed permanent magnet synchronous motors. The losses are
decreased by the proposed procedure, i.e. proper allocation of the available
stator current capacity to the direct and quadrature current components. The
approach provides increased energy efficiency by varying the ratio between
copper and iron losses.
Analytic models of CMOS logic in various regimes
Authors: Dokic Branko , Pesic-Brdjanin Tatjana , Dabic Rados
Published: May 2014

In this paper, comparative analytic models of static and dynamic
characteristics of CMOS digital circuits in strong, weak and mixed inversion
regime have been described. Term mixed inversion is defined for the first
time. The paper shows that there is an analogy in behavior and functional
dependencies of parameters in all three CMOS regimes. Comparative
characteristics of power consumption and speed in static regimes are given.
Dependency of threshold voltage and logic delay time on temperature has been
analyzed. Dynamic model with constant current is proposed. It is shown that
digital circuits with dynamic threshold voltage of MOS transistor (DT-CMOS)
have better logic delay characteristics. The analysis is based on simplified
current-voltage MOS transistor models in strong and weak inversion regimes,
as well as PSPICE software using 180 nm technology parameters.
Designing Inter-Organizational Networks to Implement Education Reform
Authors: Russell Jennifer Lin , Meredith Julie , Childs Joshua , Stein Mary Kay , Prine Deanna Weber
Published: May 2014

This study sought to understand the opportunities and challenges associated with the implementation of state designed Race to the Top (RttT) funded reform networks. Drawing on a conceptual framework developed from the networked governance literature, we analyzed the 12 state RttT grantees’ applications. Our analysis revealed that states designed large implementation networks with potential to bring a wide range of resources to bear on reform efforts, particularly through participation of numerous nonsystem actors. However, coordinating large and diverse networks places state education agencies (SEAs) in a new and challenging role. The extent to which networks extend state capacity to support educational improvement or further complicate the work of SEAs remains an open question. We propose a model including a set of theoretical propositions to guide future research.
Weak interactions-Strong effects: Key role of hydrophobic interaction in the formation of stimuli-responsive viscoelastic gel of worm-like micelles
Authors: Saha Swapan K.
Published: May 2014

Among all the weak interactions, which are operative in the domain of chemistry, hydrophobic effect is one that leads to new structural motifs like molecular self-assemblies viz., micelles, vesicles etc. Worm-like micelles are polymer like aggregates which have been formed in aqueous surfactant solutions in the presence of additives. These are relatively new materials with exciting material properties. These stimuli-responsive viscoelastic materials are interesting from both fundamental understanding as well as application points of view. The physico-chemical properties of worm-like micelles are studied and the morphological transitions to vesicle as functions of various parameters have been investigated.DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10249 BIBECHANA 11(1) (2014) 1-7
Dark Matter and Dark Energy in the Universe
Authors: Paul BC
Published: May 2014

Cosmological and astronomical observations predict that the present Universe is passing through an accelerating phase of expansion. The Universe emerged out of an exponential phase in the very early Universe. The scalar field of the standard model of particle physics when used in cosmology admits such a phase of expansion known as inflation. The most favourable condition for inflation with scalar field to admit an Inflationary scenario is that the potential energy must dominate over the kinetic energy which one obtains with a flat potential. Thereafter the Universe enters into a matter dominated phase when the field oscillates at the minimum of the potential. But it is not possible to accommodate the present accelerating phase in the Einstein’s gravity. It is known from observational analysis that about 73 % matter is responsible for the late phase expansion and 23 % matter called Dark Matter is responsible for a stable galaxy. We discuss here the relevant fields and theories that are useful for describing the late Universe. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10374 BIBECHANA 11(1) (2014) 8-16
Relativity in cosmologically preferred frame and the UHECR paradox
Authors: Nepal Saroj
Published: May 2014

The Greisen-Zatsepin-Kuzmin (GZK) cutoff (5 × 1019eV) of special relativity in the observed ultra high energy cosmic rays (UHECR) spectrum is one of the most puzzling paradoxes in physics. Experimentally a number of cosmic ray events have been detected above this GZK limit which is known as UHECR paradox. We propose a resolution of this paradox through a modification of the relativistic kinematics keeping in mind that it should not lead to predictions different from those of special relativity in the well tested domains. It is shown that theoretical limit in UHECR spectrum can be explained in the framework of Lorentz invariance violation (LIV) theories which assume the existence of a preferred frame. The present paper proposes that the velocity of the solar system with respect to the rest frame of the universe plays a role in explaining the paradox. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10375   BIBECHANA 11(1) (2014) 17-24
Empirical model based on meteorological parameters to estimate the global solar radiation in Nepal
Authors: Adhikari Krishna R , Gurung Shekhar , Bhattarai Binod K
Published: May 2014

Solar radiation is the best option and cost effective energy resources of this globe. Only a few stations are there in developing and under developed countries including Nepal to monitor solar radiation and sunshine hours to generate a rational and accurate solar energy database. In this study, daily global solar radiation, and ubiquitous meteorological data (temperature and relative humidity) rather than rarely available sunshine hours have been used for Biratnagar, Kathmandu, Pokhara and Jumla to derive regression constants and hence to develop an empirical model. The model estimated global solar radiation is found to be in close agreement with measured values of respective sites. The estimated values were compared with Angstrom-Prescott model and examined using the statistical tools. Thus, the linear regression technique can be used to develop model at any location in the world. The resultant model may then be used to estimate the missing data of solar radiation for the respective sites and also can be used to estimate global solar radiation for the locations of similar geographic and meteorological characteristic. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10376   BIBECHANA 11(1) (2014) 25-33
Dye-sensitized solar cells sensitized with natural dye extracted from Indian Jamun
Authors: Karki Indra B , Nakarmi Jeevan J , Mandal Pradeep K , Chatterjee Suman
Published: May 2014

Dye sensitized solar cell (DSSC) is a device which absorbs light from the sun with a layer of dye molecules and directly converts into electric energy. DSSCs based on ZnO have drawn attention worldwide due to their low cost and easy preparation techniques compared to conventional silicon based photovoltaic devices. Silicon based solar cells were the most popular before the emerging of dye-sensitized solar cells. These silicon based solar cells devices have dominated photovoltaic industry until now. The objectives of this study is to make DSSC using ZnO on ITO coated glass substrate as anode and characterize the DSSC properties such as conversion efficiency, short current density, open circuit voltage, and fill factor. ZnO thin films have been prepared on Indium tin oxide (ITO) glass substrate. These films were used to construct ITO/ZnO/Natural Dye/C/ITO, DSSCs with natural anthocyanin sensitizer extracted from wild Jamun fruits. The cells show open circuit voltage (Voc) of 0.58V, short-circuit current (I sc) of 1.66 mA and 0.58 fill factor (FF) with an conversion efficiency (η) of 1.23%. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10377 BIBECHANA 11(1) (2014) 34-39
UV-vis investigation of (CTC/Orthodox/Green) tea in presence of Brij 35/Water system
Authors: Bhattarai Ajaya , Mitruka Jay Narayan , Chapagain Subas Kumar , Shrestha Prem Kumar
Published: May 2014

The precise measurements of (CTC/Orthodox/Green) Tea absorbance in presence of Brij 35/Water system at room temperature by UV-vis technique are reported. The concentrations of Brij 35 [Polyoxyethylene lauryl ether] were varied from 0.01 to 0.02 mol/lt. Tea concentration in quvette during UV-vis spectrum registration was the same. Obtained results showed a noticeable decreasing of Tea absorbance as a function of Brij 35 concentration. There is evidence of Tea absorbance in the following order: Orthodox > CTC >Green. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10378 BIBECHANA 11(1) (2014) 40-45
Structural study of liquid Sn-Tl alloys
Authors: Koirala RP , Jha IS , Singh BP , Adhikari D
Published: May 2014

The concentration fluctuations in long wavelength limit, Scc(0) and the Warren-Cowley short range order parameter (α1) are important microscopic functions which provide valuable information about the local arrangements of the constituent atoms in the alloy melts. In order to investigate the nature of atomic ordering in Sn-Tl alloy in the molten state at 723K, we have computed these functions using theoretical models. The models satisfactorily explain the small asymmetry observed in the experimental data of free energy of mixing of the alloy. The comparative study further reveals that the energy interaction parameters are temperature dependent and the Sn-Tl alloy is weakly interacting segregating system. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10379   BIBECHANA 11(1) (2014) 46-52
Fabrication of dye-sensitized solar cells from thin films of zinc oxide nanocrystalline particles and organic dye
Authors: Kafle Bhim P , Pokhrel Babu R , Gyawali Rajendra , Lamichhane Prakash , Adhikari Ravi M
Published: May 2014

Photovoltaic solar modules, which are mostly made of silicon based solar cells, are still expensive to the common people of Nepal. The high cost is, mainly, due to the processing difficulties to get pure crystalline silicon. Here, we present results on devising efficient and low-cost dye sensitized solar cells (DSSCs). The solar cells were fabricated from transparent thin film of zinc oxide (ZnO), as a semiconductor, on top of which a thin layer of synthetic organic dye was deposited for efficient light harvesting. In order to achieve the films with optimum conditions for solar cell fabrication, we prepared transparent thin films of ZnO of various thicknesses and characterized by measuring their light transmittance by UV-Visible spectrophotometry. The results clearly show variation in transmittance curves with variation in film’s thickness. Also for finding appropriate sensitizer for ZnO nanoparticles, we extensively investigated the light absorbance of synthetic organic dyes. Among the dye species investigated, Green-VS, Patent-Blue, and Black-ADLI show strong absorbance over the wide range in the visible spectrum, demonstrating prospect of utilizing for DSSCs. Then prototype solar cells from ZnO film with various thicknesses were constructed and were sensitized with the mixture of Green-VS and Black-ADLI dyes (with 1:1 ratio). The measured photo-voltage and photo-current from solar cell, from our modest ZnO film, after irradiation with 200 W commercial bulb (calibrated with Pyranometer) as a light source, were about 20 mV and 1 μA, respectively. Also, with increment of the power of radiation both the measured photo-current and photo-voltage increase. Performance of the cell in real sun condition has also been made. With the solar radiation power of 930 W, the observed photo-voltage and photo-current were ca. 230 mV and 50 μA, respectively. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10380   BIBECHANA 11(1) (2014) 53-59
Electronic structure and magnetic properties of bulk elements (Fe and Pd) and ordered binary alloys (FePd and Fe3Pd):TB-LMTO-ASA
Authors: Pandey Suraj , Kaphle Gopi Chandra , Adhikari Narayan Prasad
Published: May 2014

The binary alloys formed from the elements of Fe and Pd like FePd and Fe3Pd, have the strange electronic and magnetic properties, generally used in shape memory alloys, Computational chips, Medical purposes as well as modern technological uses. We used TB-LMTO-ASA Approach for the study of band structure and density of states of the transitional elements Fe and Pd and their ordered alloys FePd and Fe3Pd. We analyzed metallic and nonmetallic character and occupation of s, p and d electrons from the band structures and magnetic properties through the plot of density of states. Our findings show that all the elements and alloys bear metallic nature whereas bulk Palladium shows non magnetic behavior. Similarly Fe and both the ordered alloys FePd and Fe3Pd are found to be magnetic in nature with values 2.19μB, 3.49μB and 3.01μB respectively. These well agree with experimental as well as previous theoretical calculations. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10381 BIBECHANA 11(1) (2014) 60-69
Theoretical investigation on ordering nature of Cd-Bi alloys in the molten state
Authors: Koirala I , Jha IS , Singh BP
Published: May 2014

Experimental determination of thermo-physical mixing properties of binary liquid alloys is a long and expensive task that becomes more complicated for some system which may be chemically active or radioactive or even may contain scarce components. Theoretical method, on the other hand reduces the time and efforts required, and are of great importance in predicting the properties. Now we have focused on theoretical model to study of the alloying behaviour of Cd-Bi alloys in the molten state at 773K. We have used simple statistical model to report the ordering nature of Cd-Bi liquid alloys through the study of surface properties, transport properties and various thermodynamic and microscopic functions. The knowledge of surface phenomena like surface segregation and surface tension is essential for the processing of materials and productions in the metallurgical industry. At the microscopic level, transport properties such as viscosity and diffusion coefficient help to understand about the mixing behaviour of the alloys forming molten metals. Thermodynamic properties provide information on the interaction, stability and bonding strength among the constituent atoms in the alloys. The microscopic properties are useful in obtaining the microscopic information on structure of molten alloys. Our theoretical analysis gives the negative energy parameter, which is found to be temperature dependent. Negative deviation from Raoultian behaviour is observed in the computed surface tension, thermodynamic and structural parameters of the alloys. But in case of viscosity isotherm positive deviation from ideality is observed. The computed results are in good agreement with experimental data. The analysis concluded that the alloy is of weakly interacting and heterocoordinating system. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10382 BIBECHANA 11(1) (2014) 70-78
Micellization behaviour of sodium dodecyl sulphate in presence and absence of sodium sulphate and zinc sulphate in distilled water by surface tension measurement
Authors: Limbu Kuber , Shah Sujit Kumar , Bhattarai Ajaya
Published: May 2014

The accurate measurements of surface tension of sodium dodecyl sulphate (SDS) in distilled water and in presence of 0.01M Na2SO4 and 0.01M ZnSO4 at room temperature were reported by drop weight method using a stalagmometer. The critical micelle concentration (cmc) of sodium dodecyl sulphate (SDS) in distilled water was obtained higher than in presence of Na2SO4 and ZnSO4. The decrease of cmc of sodium dodecyl sulphate in the presence of salts has been discussed. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10383 BIBECHANA 11(1) (2014) 79-85
Segregation in Fe-Pd melt at 1873 K
Authors: Yadav SK , Jha LN , Adhikari D
Published: May 2014

The thermodynamic and structural properties of Fe-Pd liquid alloys at 1873 K have been computed using regular associated solution model. To compute these functions we have estimated the mole fractions of the complex assuming the existence of FePd3 complex in the melt. The thermodynamic properties such as free energy of mixing (GM), heat of mixing (HM), entropy of mixing (SM) and activity (a) of the melt have been estimated. To understand the microscopic structural properties, we have estimated the concentration fluctuation in long wavelength limit (Scc(0)) and the Warren-Cowley short range parameter (α1). The free energy of mixing was found to be negative at all compositions. But the heat of mixing and the entropy of mixing are found to be positive at all compositions. The equilibrium constant (K) is found be less than negative. The interaction energy parameters (w12, w13 and w23) are all found to be positive and temperature dependent. The theoretical estimation of the concentration fluctuation in long wavelength limit (SCC (0)) is found to be greater than the ideal values throughout the whole range. The theoretical analysis suggests that the Fe-Pd liquid alloy at 1873 K near the melting point is segregating (homo-coordinating) system. The Warren-Cowley short range order parameter is found to be positive which too suggest the homocoordinating (segregating) nature of the system at all compositions. The theoretical analysis also suggests that the Fe-Pd liquid alloy near melting point is weakly interacting system. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10386   BIBECHANA 11(1) (2014) 86-93
Study on the soil corrosivity towards the buried water supply pipelines in Madhyapur Thimi municipality, Bhaktapur
Authors: Dahal Kumar P , KC Dinesh , Bhattarai Jagadeesh
Published: May 2014

This research work is carried out to identify the corrosive nature of soils towards the buried-galvanized steel and cast iron pipelines buried in Sanothimi areas of Madhyapur Thimi municipality, Bhaktapur based on different soil parameters such as organic content, moisture content, pH, resistivity, oxidation-reduction potential, chloride and sulfate ions. The soil parameters of the collected soil samples from the study areas were analyzed using standard ASTM methods. Concentrations of these soil parameters measured in this study were found as: organic content (0.9- 7.9%), moisture content (8.0-36.7%), pH (6.8-7.7), resistivity (3900-16700 ohm.cm), oxidation-reduction potential (337-461 mV vs SHE), chloride (25-71 ppm) and sulfate (35-464 ppm) contents. These soil parameters gave an indication of “mildly corrosive” to “less corrosive” nature of soils on the galvanized steels and cast iron pipelines buried in the study areas. Based on the findings of the present studies, it can be advised to the related authorities or local people that simple modification of the soils by using cheapest non-conducting materials like gravel or sand around the buried water supply pipelines before undergrounding them in the study areas is very beneficial from the corrosion point of view to increase their life time. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10387 BIBECHANA 11(1) (2014) 94-102
Critical micelle concentration of sodium dodecyl sulphate in pure water and in methanol-water mixed solvent media in presence and absence of KCl by surface tension and viscosity methods
Authors: Niraula Tulasi Prasad , Bhattarai Ajaya , Chatterjee Sujeet Kumar
Published: May 2014

Careful measurements of surface tension and viscosity of sodium dodecyl sulphate (SDS) in presence and absence of KCl in pure water and methanol-water mixed solvent media containing 0.1, 0.2, 0.3 and 0.4 volume fractions of methanol at 308.15 K are reported. The concentration of KCl is 0.01M. The concentration of SDS varies from 4.86×10-3 to 29.56×10-3 mol.l-1. The critical micelle concentration (cmc) increases with increase in percentage of methanol and decreases with addition of salt. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10388 BIBECHANA 11(1) (2014) 103-112
Hydrogen storage on platinum decorated graphene: A first-principles study
Authors: Lamichhane S , Pantha N , Adhikari NP
Published: May 2014

Adsorption of gaseous/molecular hydrogen on platinum (Pt) decorated and pristine graphene have been studied systematically by using density functional theory (DFT) level of calculations implemented by Quantum ESPRESSO codes. The Perdew-Burke-Ernzerhof (PBE) type generalized gradient approximation (GGA) exchange-correlation functional and London dispersion forces have been incorporated in the DFT-D2 level of algorithm for short and long range electron-electron interactions, respectively. With reference to the binding energy of Pt on different symmetry sites of graphene supercells, the bridge (B) site has been predicted as the best adsorption site. In case of 3×3 supercell of graphene (used for detail calculations), the binding energy has been estimated as 2.02 eV. The band structure and density of states calculations of Pt adatom graphene predict changes in electronic/magnetic properties caused by the atom (Pt). The adatom (Pt) also enhances the binding energy per hydrogen molecule in Pt-graphene comparing to that in pristine graphene and records the values within the range of 1.84 eV to 0.13 eV for one to eight molecules, respectively. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10389 BIBECHANA 11(1) (2014) 113-122
Study of critical micelle concentration of cetyltrimethylammonium bromide (CTAB) in pure water in presence and absence of magnesium sulphate and sodium sulphae by measuring conductivity meter
Authors: Bhattarai Ajaya , Shrivastav Ghanashyam , Adhikari Chom Nath
Published: May 2014

The precise measurement of specific conductivity of cetyltrimethylammonium bromide (CTAB) in distilled water at room temperature was reported and also the specific conductivity of cetyltrimethylammonium bromide was measured in the presence of magnesium sulphate and sodium sulphate using a conductivity meter. The critical micelle concentration of three systems was calculated. The comparison of cmc among them was also performed. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10390 BIBECHANA 11(1) (2014) 123-127
Determination of critical micelle concentration of cetyltrimethylammonium bromide in presence and absence of KCl and NaCl in aqueous media at room temperature by viscosity measurement
Authors: Jha Kabita , Bhattarai Ajaya , Chatterjee Sujeet Kumar
Published: May 2014

NOTE: The correct reference list was added to this article on 08/07/2014.Viscosity measurement of cetyltrimethylammonium bromide in presence and in absence of KCl and NaCl in aqueous media is done. The results showed a sharp increase in viscosity with increase in concentration of cetyltrimethylammonium bromide. Also, the viscosity increases with addition of salts. The viscosity of cetyltrimethylammonium bromide is found more in presence of KCl than NaCl in aqueous media. In presence of monovalent salts, the critical micelle concentration (cmc) value decreases which is explained on the basis of nature and ionic strength of the added ion. The graphs of viscosity versus concentration are used in determining the critical micelle concentration (cmc). DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10392BIBECHANA 11(1) (2014) 131-135