186 research outputs found
Relationships Between the profitability and Safety of Ships
http://deepblue.lib.umich.edu/bitstream/2027.42/96595/1/39015087358688.pd
Asia’s Colonial Photographies
Almost immediately after the invention of photography in 1839, photographers embarked on expeditions throughout the colonial world. Entrepreneurial photographers rushed to locations along the colonial trail across the Middle East, Africa, the Americas, the Pacific, and Asia, to create images of ancient monuments and ‘exotic others’. They created lavish albums of photographs, making available pieces of the periphery for sale in European metropoles. Colonised people and places became the ongoing subjects of the colonial lens
Thermal Conversion of Guanylurea Dicyanamide into Graphitic Carbon Nitride via Prototype CNx Precursors
Guanylurea dicyanamide, [(H2N)C(-O)NHC(NH2)2][N(CN)2], has been synthesized by ion exchange reaction in aqueous solution and structurally characterized by single-crystal X-ray diffraction (C2/c, a = 2249.0(5) pm, b = 483.9(1) pm, c = 1382.4(3) pm, β = 99.49(3)°, V = 1483.8(5) × 106 pm3, T = 130 K). The thermal behavior of the molecular salt has been studied by thermal analysis, temperature-programmed X-ray powder diffraction, FTIR spectroscopy, and mass spectrometry between room temperature and 823 K. The results were interpreted on a molecular level in terms of a sequence of thermally induced addition, cyclization, and elimination reactions. As a consequence, melamine (2,4,6-triamino-1,3,5-triazine) is formed with concomitant loss of HNCO. Further condensation of melamine yields the prototypic CNx precursor melem (2,6,10-triamino-s-heptazine, C6N7(NH2)3), which alongside varying amounts of directly formed CNxHy material transforms into layered CNxHy phases without significant integration of oxygen into the core framework owing to the evaporation of HNCO. Thus, further evidence can be added to melamine and its condensation product melem acting as “key intermediates” in the synthetic pathway toward graphitic CNxHy materials, whose exact constitution is still a point at issue. Due to the characteristic formation process and hydrogen content a close relationship with the polymer melon is evident. In particular, the thermal transformation of guanylurea dicyanamide clearly demonstrates that the formation of volatile compounds such as HNCO during thermal decomposition may render a large variety of previously not considered molecular compounds suitable CNx precursors despite the presence of oxygen in the starting material
Journal of Advances in Medical and Pharmaceutical Sciences
Aim: To evaluate the effects of graded doses of ethanolic stem bark extract of Picralima nitida on haematological profile, some serum reproductive hormones, sperm reserves and testicular histomorphology of male albino rats.
Study Design: Thirty male albino rats, weighing between 120 and 200 grams were randomly assigned into six groups of five rats each. Group A received 0.5 ml of distilled water (normal control). Groups B, C and D received 100, 200 and 400 mg/kg BW of the extract respectively. Group E received 2.5 mg/kg BW of CdCl2 (negative control), while Group F received 5 mg/kg BW of Sildenafil (positive control); orally every other day for six weeks.
Place and Duration of Study: Department of Veterinary Physiology and Pharmacology (Laboratory Animal Unit), University of Nigeria, Nsukka, between June and September, 2015.
Methodology: At the end of the experiment, blood samples were collected for haematology and serology, whereas testicular sections were collected for histopathology following the standards procedures. Data obtained were analyzed by One-way ANOVA.
Results: The result showed that all doses of the extract increased neutrophil count, but decreased (P < 0.05) monocyte and RBC counts; 200 and 400 mg/kg BW of the extract decreased (P < 0.05) PCV values; and only 400 mg/kg of the extract reduced (P < 0.05) HB values. 200 and 400 mg/kg BW of the extract, and 2.5 mg/kg BW of CdCl2 decreased (P < 0.05) serum testosterone and sperm counts. The normal control, 100 mg/kg BW of the extract and 5 mg/kg BW of Sildenafil had normal testicular histoarchitecture; whereas 200 and 400 mg/kg BW of the extract, and 2.5 mg/kg BW of CdCl2 had slight, moderate and severe degeneration of the germinal epithelium and interstitium, with depletion of sperm cells in the lumen of the seminiferous tubules respectively.
Conclusion: This study revealed that treatment with ethanolic stem bark extract of Picralima nitida above 100 mg/kg BW adversely affected haematological and reproductive parameters in male albino rats
Sediment Quality of Orashi River at Four Oil Producing Communities of Nigeria
Bed Sediment samples were collected in the Dry Season from Orashi River
at three sampling sites each located in Mmahu, Opuoma, Abacheke and
Ogwu Aniocha communities. Physicochemical parameters, hydrocarbon and
heavy metal (As, Cd, Fe and Pb) concentrations were determined with
standard methods. Results showed that total petroleum hydrocarbon (TPH)
ranged from 0.11 \ub10.03 to 1.91 \ub10.25 mg/kg while total
hydrocarbon content (THC) and oil and grease had ranges of 0.28
\ub10.06-2.98 \ub10.19 and 0.69 \ub10.09-3.60 \ub10.57 mg/kg
respectively. The sediment samples were classified as unpolluted in
terms of TPH. Mean values for pH had a range of 4.33 \ub10.22 - 6.60
\ub10.52 while the texture of most samples was sandy. Mean organic
carbon contents ranged from 0.58\ub10.07 to 3.15\ub10.66 % and mean
total nitrogen and total phosphorus had ranges of 0.30\ub10.00
-2.77\ub10.46 and 17.34\ub11.65 - 29.48\ub11.63 mg/kg
respectively. Mean Mg concentrations were significantly higher
(P<0.05) than the concentrations of other exchangeable bases and
mean As concentration had a range of 1.175\ub10.086-1.291\ub10.335
mg/kg. Mean Cd concentrations ranged from 0.948\ub10.072 to
3.120\ub10.131 mg/kg while mean Fe and Pb concentrations had ranges
of 57.324\ub110.530-159.707\ub141.192 and
1.300\ub10.295-7.462\ub10.861 mg/kg respectively. As and Pb values
were lower than the sediment quality guidelines (SQG) but Cd values
were higher than the guidelines in all sites. Contamination factors
(CFs) for As and Pb indicated low contamination while CFs for Cd
indicated moderate to considerable contamination. Geo-accumulation
index (Igeo) values for As and Pb at all sites and that of Cd at one
site indicated unpolluted, Igeo values for Cd at all other sites ranged
between 0.210 and 1.571 indicating unpolluted to moderately polluted
status
Ascertaining the Overall Occurrence of Dental Fluorosis in Students of Selected Secondary Schools in Rivers State
Public health places a premium on understanding the amount of fluoride in potable water and other toothpastes, as well as how it affects skeletal and dental tissues to cause fluorosis. Fluorosis is, however, poorly understood and known in Nigeria. The goal of this research was to Ascertain the Overall Occurrence of Dental Fluorosis in Students of Selected Secondary Schools in Rivers State. A cross-sectional survey of 541 students from selected secondary schools in Rivers State who were between the ages of 9 and 17 was carried out. All students present at school on the day of data collection had their mouths examined by oral health professionals as part of a quasi-experimental method. Each subject was supported by a torch light while seated on a chair, and their teeth were examined for dental fluorosis in their wet state. The presence of dental fluorosis and the severity of it were documented using Dean's Dental Fluorosis. The presence of dental fluorosis and the severity of it were documented using Dean's Dental Fluorosis. (358) Dental fluorosis impacted 66.17% of the students, varying in severity from very mild to severe cases
Antenatal care and women’s decision making power as determinants of institutional delivery in rural area of Western Ethiopia
Psychometric Assessment of Lee Yew’s Leadership Role in Singapore’s Development: A Systematic Review
This study sought psychometric evidence to prove this assertion. Consequently, the leadership attributes of Lee Kuan Yew, the first and longest-serving Prime Minister of Singapore, and the impacts he made on Singapore’s development were explored. Some of the research questions addressed are: What are the valid indicators of development in Singapore at inception and thirty years after? What are the leadership factors that facilitated Singapore’s development? What are the cultural factors that facilitated Yew’s achievement? The concept of Development encompasses various theories in different disciplines and contexts - the Economic Development theory of development, the Human Development and Human Development Index (HDI), the Gross National Happiness (GNH) model, the Dependency theory, the Sustainable Development, and the Participatory Development theory. Likewise, the concept of Leadership encompasses various theories – The Contingency and Situational Leadership theory, and the Ethical leadership theory. The systematic review design was adopted by selecting and analyzing 10 relevant studies gotten from electronic databases, including EBSCO, Scopus, Web of Science, and Sage. Singapore indeed experienced remarkable development within a short space of 30 years, literally leapfrogging from squalor to attainment of GDP which surpassed that of United Kingdom; There were indeed many notable leadership qualities in Lee Yew that instigated the crafting of wise policies and strategies cum dogged implementation drives that led to the remarkable development of Singapore; Some cultural factors that facilitated Yew’s leadership efforts in achieving Singapore’s development were identified. The study provided ample evidences that, given the right conditions, which can always be created by a make-things-happen leader like Lee Yew, everything indeed rises and falls on leadership acumen. This study contributes to existing literature by conducting a systematic review on Lee Yaw’s leadership role in the development of Singapore
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