Pulsar Glitch Activities:The Spin Parameters Approach

Glitch activity refers to the mean increase in pulsar spin frequency per year due to rotational glitches.It is an important tool for studying super-nuclear matter using neutron star interiors as templates.Glitch events are typically observed in the spin frequency(ν) and frequency derivative( ν) of pulsars.The rate of glitch recurrence decreases as the pulsar ages,and the activity parameter is usually measured by linear regression of cumulative glitches over a given period.This method is effective for pulsars with multiple regular glitch events.However,due to the scarcity of glitch events and the difficulty of monitoring all known pulsars,only a few have multiple records of glitch events.This limits the use of the activity parameter in studying neutron star interiors with multiple pulsars.In this study,we examined the relationship between the activity parameters and pulsar spin parameters(spin frequency,frequency derivative,and pulsar characteristic age).We found that a quadratic function provides a better fit for the relationship between activity parameters and spin parameters than the commonly used linear functions.Using this information,we were able to estimate the activity parameters of other pulsars that do not have records of glitches.Our analysis shows that the relationship between the estimated activity parameters and pulsar spin parameters is consistent with that of the observed activity parameters in the ensemble of pulsars.

Heavy Metal Levels and Ecological Risk in Crude Oil-Contaminated Soils from Okpare-Olomu, Niger Delta, Nigeria

Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the presence of metallic ions. The Okpare-Olomu community has borne the brunt of crude oil pollution from illicit bunkering, sabotage, and equipment malfunction. This study targets an evaluation of ecological hazards linked to heavy metals (HMs) in crude oil impacted agriculturally soils within Okpare-Olomu in Ughelli South LGA of Delta State. In this study, 24 topsoil samples were obtained from areas affected by crude oil pollution;the heavy metal content was evaluated through atomic absorption spectrometry. The concentration ranges for HMs (mg/kg) in soil were: 24.1 - 23,174 (Cu);0.54 - 37.1 (Cd);9.05 - 54 (Cr);12 - 174 (Ni);18.5 - 8611 (Pb);and 148 - 9078 (Zn) at a soil depth of 0 - 15 cm. Notably, metal concentrations were recorded to be above permissible World Health Organization limits. Predominantly, Zn and Pb recorded higher heavy metal concentration when compared to other heavy metals analysed, notably at sampling points PT7 through PT24. Zinc and Pb contamination exhibited highly significant contamination factors, and contamination severity was evidenced across all sample points, signifying a grave risk level. Pollution load indices indicated pervasive extreme pollution levels. Geoaccumulation indices signaled moderate to strong pollution, mainly by Pb and Zn. Ecological risk assessments revealed variable levels of heavy metal contamination, from low to very high, with potential ecological risk reflecting markedly elevated levels. This study underscores the imperative for soil remediation to rectify ecological imbalances in agriculturally affected soil constituents.

Genetic Disposition: Susceptibility of Human Blood Groups and Abo Analysis to Malaria and Typhoid Infections

Background: Malaria and typhoid have remained major infectious tropical diseases. Clinically, whenever there is severe malaria, cough is always an associating symptom owing to typhoid infection arising from poor hygiene in respect to drinking water and food. There is a strong association between human blood group and disease. Residual malaria transmission, effect of climate change on malaria vector composition, environmental management targeted at malaria breeding control as an intervention strategy are areas of interest to WHO in malaria control in Sub-saharan Africa. A body of data is been built on susceptibility of human blood groups to malaria, HIV and HBV and presently malaria and typhoid. If climate change warrants a change in composition of vectors and as well resistance to ACT therapy, the susceptibility or vulnerability of the human blood group is also called to question. The link between susceptibility of human blood group to malaria and typhoid has not been previously investigated. Purpose: The present study assesses the genetic disposition (susceptibility of human blood groups and abo analysis) to malaria and typhoid infections. Patients and Methods: One hundred (100) patients were screened for malaria and typhoid infections in a tertiary health facility—His glory hospital Lagos, Nigeria. Blood samples were collected by venu-puncture from 53 females and 47 males adults aged between 15 – 47 years, who were infected either singly or coinfected with malaria and typhoid. Microscopic detection of P. falciparum, widal serological technique for salmonella antibody presence and genotypic determination were all done using standard WHO methods. Human material or data were analyzed or performed in accordance with the declaration of Helsinki (2000). Ethical clearance was obtained from the ethic and research committee of the Ministry of Health via the Faculty of the Basic Medical Sciences, University of Calabar (Ethical Certificate number CRS/MOH/HRP/2023/396). Results: The results obtained expressed in percentage frequency show that genotype AA were more susceptible to typhoid and malaria infections compared to AS and SS, also blood group O was more susceptible to malaria and typhoid infection compared to blood groups A, AB and B, although, there is no significant difference between male and female gender, susceptibility to malaria infection, the female gender is more susceptible to typhoid than the male. The finding may be relevant to malaria susceptibility and genetics and thus provide baseline information on management of the scourge. Conclusion: We conclude that genotype AA and blood group 0+ are more susceptible to malaria and typhoid infection in humans.

Assessment of Rainwater Quality in Warri and Environ, Southern Nigeria for Domestic Purposes

The study aimed at assessing the physiochemical characteristics of rainwater in Warri and it environ was investigated. Pb, Zn, Cd, Cu and Cr concentrations in rainwater from roof and non-roof sources were determined using Atomic Absorption Spectrophotometry. Three geospatial locations comprising Jakpa, Udu, and Ubeji were selected based on prevailing anthropogenic activities. The rainwater samples were systematically collected from (aluminum) roof and non-roof sources for the months of April, June, and August and October 2022, treated and analyzed in the laboratory for sixteen physicochemical parameters. Results were statistically analyzed using ANOVA, and T-test for the determination of the level of relationships and variations across geospatial locations. Significant correlations (r = 0.72) exist between Cr in rainwater from roof and non-roof sources. Implying point-source contaminations and may be emanating from the influence of roof materials. Furthermore, high concentrations of Cd and Pb in roof source above WHO standards were mostly in Jakpa and Ubeji. Calculated Health Risk Index (HRI) for children and adult is greater than 1. The results showed that most samples from the locations are considered not safe (HRI > 1) especially for Cd, which means that there are potential health risks consuming rainwater from Jakpa, Udu and Ubeji. Therefore, there is need for prompt sensitization program to dissuade people from directly drinking rainwater from these locations.

球形表面富锰Mn_(x)Co_(3-x)O_(4-η)尖晶石型催化剂选择性催化还原NO_(x)研究

采用共沉淀法制备了高比表面积的Mn_(x)Co_(3-x)O_(4)球形催化剂,研究了NH3选择性催化还原NOx性能。Mn-Co金属氧化物具有尖晶石结构,随着Co含量的增加,晶体结构由四方相转变为立方相。高浓度的表面活性氧物种和变价元素的强有效电子转移(Co^(3+)+Mn^(3+)↔Co^(2+)+Mn^(4+))有利于提高Mn_(x)Co_(3-x)O_(4)(x=1.0、1.5、2.0)尖晶型石催化剂的氧化还原能力,催化剂表面的Mn富集作用形成了氧缺陷结构和丰富的表面活性位点,进一步促进SCR脱硝反应,呈现出优异的催化性能。COtet(CoMn)octO_(4)晶体结构中,Mn离子(Mn^(3+)和Mn^(4+),以三价锰为主)和部分Co离子被配置到八面体中心,这些物种作为活性位点存在着较强的电子转移交互作用,该构型对促进低温脱硝活性和保护活性位点耐受SO_(2)毒害具有重要的意义。Mn-Co尖晶石表面的NH_(3)-SCR脱硝反应过程主要遵循Eley-Rideal反应机理,即吸附态NH_(3)与气态NO(或NO_(2))的反应路径。随着反应温度的增加,反应生成的NH_(4)NO_(3)中间体很可能转化为NH_(4)NO_(2)物种,进而分解为N_(2),提高了催化剂的氮气选择性。

Mechanisms of medicinal plants in the treatment of diabetic wound

Wound repair is noticeably prolonged in a diabetic state due to a faulty inflammatory process and an underlying neuropathy.Several medicinal plants and their products have been of prime importance for the management of wounds over the years.Various mechanisms whereby medicinal plants elicit their action in wound repair are revealed and some plants are proven to be experimentally effective in enhancing wound closure and achieving healing.The mechanisms identified include hyperglycemic control,alleviation of physiological inflammation,controlled oxidative stress,infection control,and influence on gene expression.Information in this review was sourced from research and review articles in electronic databases such as Web of Science,Scopus,PubMed,and Google Scholar.

Outdoor Corrosion Performance Study of Selected Construction Materials in Bonny Island

Corrosion studies are important due to the enormous cost involved in the replacement of materials in all kinds of applications. The outdoor study on corrosion behavior of aluminum sheet, chequered aluminum plate and zinc alloys roofing sheet commonly used as construction material within a highly industrial settlement were examined using the gravimetric technique. The outdoor corrosion of these alloys at different sites was observed via its exposure to atmospheric conditions, monitored and recorded for 12 months at an interval of 2 months. Results depicted a process spanning the initial and intermediate stages of corrosion. The samples of construction materials at Bonny island showed substantial weight losses and rate of corrosion which varied largely on percentage of atmospheric humidity, salt precipitations, industrial aerosols and corrosive gases present at the exposure site as well as the nature of the material and the presence of protective coating formed during corrosion process. The rapid rate of deterioration of these materials causes severe economic importance on the indigenes’ activities including the oil and gas industries and other construction companies on the island. Thus, there is urgent need for research concerned with methods to control or prevent excessive deterioration of metals in Bonny Island.

Kinetics of Bioremediation of Oil Contaminated Water Dispersed by Environment-Friendly Bacteria (Pseudomonas aeruginosa) and Fungi (Aspergillus niger)

The comparative effectiveness of remediating water polluted with crude oil, using environment-friendly bacteria (Pseudomonas aeruginosa) and fungi (Aspergillus niger) were investigated. The samples were separately treated with Aspergillus niger and Pseudomonas aeruginosa. The bioremediation kinetic efficiency for these systems was studied. At the end of the bioremediation periods, the oil and grease content of the samples decreased from 47.0 mg/L in the untreated sample to 7.0 mg/L after 20 days when inoculated with bacteria while the sample inoculated with fungi decreased to 10.0 mg/L. Post analysis when inoculated with bacteria showed a fall in the value of the biological oxygen demand (BOD) from 73.84 mg/L to 33.28 mg/L after 20 days, while, the fungi inoculated sample showed a reduction from 73.84 mg/L to 38.48 mg/L. The biodegradation process with the bacteria was consistent with the pseudo-first-order model with a rate constant of 0.0891 day-1, while the biodegradation process with the fungi was consistent with the first order reaction model with a rate constant of 0.422 day-1. The degree of degradation after the 20th day of inoculation with Pseudomonas aeruginosa was 85.11%, while with Aspergillus niger was 78.72%. Thus, the results obtained showed that, Pseudomonas aeruginosa performed better than Aspergillus niger. The bioremediation data with fungi fitted the first-order model, while that of the bacteria fitted the pseudo-first-order model. Therefore, the data obtained in this study could be applied in the design of a bioremediation system for potential application to remediation of crude oil polluted water.

Prevalence and Associated Risk Factors of COVID-19 in an Incarcerated Population Burdened with HIV Infections in Port Harcourt

Background: The burden of COVID-19 and human immunodeficiency virus (HIV) are some of the major and persistent global health challenges of the twenty-first century. HIV and COVID-19 are expected to overlap in high HIV-burden countries, posing several public health challenges as a result. Prisons are overcrowded, have limited space for social distancing and have inadequate ventilation systems, making it difficult to contain the spread of COVID-19 in addition to the high-risk behaviours of inmates which contribute to the spread of HIV within these facilities. This study aimed to determine the prevalence of COVID-19 among inmates in a prison facility with a relatively high HIV burden in Port Harcourt, Nigeria;investigating potential risk factors and co-infection with HIV. Methodology: The study employed a descriptive cross-sectional study design sampling 200 inmates from the Port Harcourt Maximum Security Custodial Centre from July to December 2022. A well-structured questionnaire was administered via interviews in addition to screening for HIV-1/2 antibodies as well as COVID-19 antigens using rapid diagnostic test kits. Descriptive statistics and chi-square were carried out on the GraphPad Prism 9 software with statistical significance defined as a p-value of less than 0.05 at a 95% confidence interval. Result: The prevalence of HIV from the current study was 6.5%, COVID-19 prevalence was reported to be 12.5% while HIV/COVID-19 co-infection was 1.5% The duration of incarceration, face mask use, frequent visitations and vaccination against COVID-19 were found to be significantly associated with the prevalence of COVID-19 in the studied population (p Conclusion: The current study reports a relatively high prevalence of HIV and COVID-19 among the inmates in the study area. It becomes expedient for the administrators of the correctional facility to properly screen new inmates for COVID-19, quarantine and manage cases, as well as provide them with personal protective equipment such as face masks. In-person visitation should be balanced with measures to prevent the spread of the infection, and mass vaccination campaigns should be promoted. Improving access to HIV screening and therapy for all prisoners should be prioritised to identify and manage the incidence of HIV early, reducing the risk of transmission, mitigating comorbidities and improving health outcomes.

Analgesic and anti-inflammatory activities of the ethanol extract of the leaves of Helianthus Annus in Wistar rats

Objective:To investigate the anti-inflammatory and analgesic effects of the ethanol extract of leaves of Helianthus annus L.(H.annus) in acclimatized Wistar rats.Methods:It was undertaken using the albumin induced paw edema model of inflammation as well as both the hotplate and tail immersion analgesic test methods.Doses of the extract tested in experimental rats were 0.5 g/kg,2 g/kg and 4 g/kg while negative and positive control rats received distilled water and indomethacin respectively.Results:It was shown that treatment with the tested doses of the extract effectively inhibited paw edema induced by egg albumin.This effect was comparable if not better than the observations made in rats treated with 10 mg/kg of indomethacin orally.Treatment with the extract was also observed to have significantly increased the mean tolerance time of rats to thermal noxious stimuli compared to control animals that had distilled water and appeared to be more effective than 10 mg/kg of indomethacin treatment.Conclusions: These observations confirmed the presence of a strong anti-inflammatory and anti-noiciceptive activity in the ethanol extract of the leaves of H.annus and therefore validated the folkloric use of the leaves of this plant in treatment of pro-inflammatory,post traumatic situations.

On the distributions of pulsar glitch sizes and the inter-glitch time intervals

The glitch size,△ν/ν, inter-glitch time interval, ti, and frequency of glitches in pulsars are key parameters in discussing glitch phenomena. In this paper, the glitch sizes and inter-glitch time intervals are statistically analyzed in a sample of 168 pulsars with a total of 483 glitches. The glitches are broadly divided into two groups. Those with △ν/ν< 10^-7 are regarded as small size glitches, while those with△ν/ν≥ 10^-7 are considered as relatively large size glitches. In the ensemble of glitches, the distribution of△ν/ν is seen to be bimodal as usual. The distribution of inter-glitch time intervals is unimodal and the interglitch time intervals between small and large size glitches are not significantly different from each other.This observation shows that inter-glitch time intervals are size independent. In addition, the distribution of the ratio △ν/ν: tiin both small and large size glitches has the same pattern. This observation suggests that a parameter which depends on time, which could be the spin-down rate of a pulsar, plays a similar role in the processes that regulate both small and large size glitches. Equally, this could be an indication that a single physical mechanism, which could produce varying glitch sizes at similar time-intervals, could be responsible for both classes of glitch sizes.

Effects of ethanol extract of leaves of Helianthus annus on the fecundity of Wistar rats

Objective:To evaluate the effects of ethanol extract of leaves of Helianthus annus(H.annus) on the fecundity of Wistar rats.Methods:Forty(20 male and 20 female) Wistar rats,grouped into control,ethanol extract treated rats and untreated,were used for the study.Treated rats had 0.5 g/kg of ethanol extract orally for 2 weeks;control rats had 5%alcoholic water(solvent);and untreated rats had their normal feed and clean drinking water.Following treatment,the animals were sub-grouped into 5 mating groups to observe the coital frequency,pregnancy rate and average number of pups per group in pairs.Results:The results showed that coital frequency was unaffected by the extract treatment but pregnancy rate and number of pups per rat and per group were reduced significantly in groupsⅡ,ⅢandⅣcompared to those of groupⅠandⅤrats which were not treated with the ethanol extract of leaves of H.annus.Conclusions:The histodegenerative in the gonads reportedly induced by this ethanol extract in previous studies may be responsible for the reduced fecundity observed in treated adult rats.

Comparison of Phytochemicals and Anti-Nutritional Factors in Some Selected Wild and Edible Bean in Nigeria

This work aims at analyzing the bioactive and anti-nutritional compounds of edible and wild beans when unprocessed and malted. Qualitative screening of phytochemicals in the various bean samples was determined in ethanol and petroleum ether solvents. Results of the anti-nutritional compositions of unprocessed wild bean extracted with petroleum ether showed there were no traces of saponin and polyphenol, in Feregede and also in edible bean-IT07K-243-1-10 which also had no traces of saponin and tannin. After malting, saponin was totally absent in Pakala, Mucuna, IT97k-499-35, IT07k-243-1-10, and IT04k-333-2 respectively. Polyphenol was also found to be absent in IT07k-243-1-10. Mucuna has the highest phytic acid level (7.8867 ± 0.011) while Feregede has the lowest phytic acid level (2.9810 ± 0.004). Otili has the highest anti-trypsin level (12.001 ± 0.0013). This study showed varying levels of anti-nutrients on the respective bean samples when unprocessed but decreased marginally after malting. It was keenly noted that values derived, either before and after malting were not significantly different (P ≤ 0.05) from each other. In all, this study had further shown that malting process enhanced removal of anti-nutrients which invariably would lead to availability of nutrient for animal and human consumption.

C-glycosyl flavonoid orientin alleviates learning and memory impairment by radiofrequency electromagnetic radiation in mice via improving antioxidant defence mechanism

Objective: To investigate the antioxidant efficacy of oral orientin on 900 MHz radiofrequencyelectromagnetic radiation-induced oxidative stress in mice.Methods: The mice were randomly allotted into 5 groups consisting of 7 mice each. The deionised water and radiofrequency electromagnetic radiations(RF-EMR) groups were administered with deionised water while orientin was administered to the RF-EMR + low dose of orientin group(10 mg/kg), RF-EMR + high dose of orientin group(20 mg/kg) and high dose of orientin group(20 mg/kg). All the groups except deionised water and high dose groups were exposed to 900 MHz radiofrequency-electromagnetic radiation for 28 consecutive days(1 h/day). Learning and memory was assessed via the step-down inhibitory avoidance task. Activities of lipid prexidation and antioxidant enzymes were measured using kits.Results: Radiofrequency electromagnetic radiation caused impairment in learning and memory and reduced activities of brain antioxidant enzymes, increased lipoperoxidation and corticosterone concentration as well as histopathological aberrations in the hippocampal tissues. Conversely, orientin alleviated learning and memory deficit, improved the activities of endogenous antioxidant enzymes and mitigated brain lipoperoxidation and neuronal degeneration in mice exposed to radiofrequency electromagnetic radiation. Conclusions: Orientin alleviates learning and memory impairment due to radiofrequency electromagnetic radiation in mice by improving antioxidant defence mechanism and may be considered as a promising therapeutic agent for improving the antioxidant system of people living in radiofrequency electromagnetic radiation-prone environment.

Assessment of trace metals contamination in stream sediments and soils in Abuja leather mining, southwestern Nigeria

This study is aimed at determining the level of environmental degradation as well as the concentration of trace elements in soil and stream sediments in order to evaluate the environmental impact of the mining operation.Twenty-five(25) soils and ten(10) stream sediment samples were collected from the study area. The physicochemical parameters were determined using appropriate instrumentation with the aid of a digital p H meter(Milwaukee meter) to measure the p H and electrical conductivity, total dissolved solids, moisture content and loss on ignition of the soil and stream sediment samples. The p H of the soil sample ranged from(6.10 to 7.19); Electrical conductivity ranged from(21.3 to 279.4 μS/cm), moisture content varied from(0.60% to 7.20%), and the LOI ranged from(2.03% to 18.62%). The results of the analysis showed that the concentrations of the trace elements in the soils and stream sediment samples were slightly higher than the background values. Plots of the trace elements in stream sediment samples show moderate, consistent decrease downstream except at points where there was mine water discharge into the main river. The pollution levels of heavy metals were examined in stream sediment and soil samples using different assessable indices, such as the enrichment factor, which showed significant-moderate enrichment for Cr, Th, Nb, Zn, Pb, Y and Zr and the geoaccumulation index, which showed practically moderate contamination with Cr, Ni and Sr based on regional background reference values. Geo-accumulation index and contamination index for soils and stream sediment revealed uncontaminated to moderate contamination. Likewise,elements with moderate contamination were Cr, Ni and Sr.The Pearson correlation showed that there were significant positive associations among selected metals in soil and stream sediment samples.

Water Analysis for Heavy Metals Content in Selected Boreholes in Port Harcourt Metropolis （A Case Study during 2010-2011）

Underground water （Borehole） has been the main alternative source of drinking water for most communities in my country. Previous studies have revealed high levels of contamination. The origin of which can be attributed to geochemical processes, combustion of fossil fuels, mining and anthropogenic activities. Most borehole water and well water in local communities of Nigeria are not safe for drinking due to heavy industrial and environmental pollution. This study was undertaken to assess the quality in some selected boreholes in the Port Harcourt metropolis for a period of two years. Borehole water samples were randomly collected from thirteen boreholes in a local community in plastic bottles （100 mL） in the months of September for the years of study （2010 ＆ 2011）. Four out of the seven heavy metals analyzed were found to be present in the first year of study. These were Fe, Cu, Mn and Zn. In the second year of study, Pb, Cr, Fe and Co were not detected in all of the samples except Cu and Fe which were present in only two samples. Mn and Zn were found to be present in all of the samples for both years of study.

Production, Quality Evaluation and Sensory Acceptability of Mixed Fruit Juice from Pawpaw and Lime

Pawpaw and lime juices were blended to produce mixed pawpaw/lime juice samples in the ratios of 90:10, 80:20, 70:30, 60:40 and 50:50) v/v giving samples A, B, C, D and E respectively. The moisture, mineral and vitamin contents, as well as the physical, microbiological and sensory qualities of the individual juices and blended samples were evaluated. While lime juice had higher moisture, calcium and vitamin C with values of 97.90%, 2.21 mg/100 g and 67.47 mg/100 g as compared to pawpaw juice with 92.96%, 1.53 mg/100 g and 35.49 mg/100 g respectively;the pawpaw juice had higher ash, phosphorus and vitamin A contents, with values of 3.12%, 54.97 mg/100 g and 5.90 IU/100 g as against 2.84%, 29.53% and 0.16% for lime juice respectively. While there was a general increase in moisture, calcium and vitamin C contents with blending, ash, phosphorus and vitamin A contents increased with increase in lime. The total solids content and specific gravity of pawpaw juice were remarkably higher at 7.04% and 1.15 g/m3 compared to 2.09% and 1.09 g/m3 respectively for lime juice. However, lime juice had a higher titratable acidity, while recording a lower pH of 2.89 as compared to 5.36 for pawpaw juice. The Total Viable Count (TVC) of lime juice was much lower (2.33 × 105 CFU/ml) than that of pawpaw juice (5.33 × 106 CFU/ml). There was significant difference (p < 0.05) in all the sensory parameters evaluated. Generally, there was an increase in the scores of each parameter from sample A to B and then a decline through to sample E. Sample B (80:20) mixed pawpaw/lime juice was most preferred, while sample E (50:50) was least preferred.

Interaction of Glucose/Sucrose Binding Lectin Isolated from Nigeria Wild Bean with <i>E. coli</i>and <i>S. aureus</i>

Lectin purified from wild underutilized local bean—Otili, Feregede, Pakalai was comparatively characterized and further evaluated for interaction with gastrointestinal bacteria—Esherichia coli and Staphylococcus aureus. The purified lectin in all the bean samples showed to be glucose and sucrose binding. The hemagglutinating activity, was non selective to type of blood group (A, B, AB and O). Anti-bacteria interaction with Escherichia coli showed clear zone of inhibition of about 1.5 ± 0.5 mm with lectin from Feregede and Otili while there was slight agglutination with lectin from Pakala. Staphylococcus aureus sensitivity to the lectin extracted from Otili with clear zone of inhibition of 2.0 ± 0.5 mm was also found in the control chloramphenicol. However there was pronounced agglutination with lectin from Feregede and Pakala with Staphylococcus auereus. This may be a clear indication that lectin from local underutilized wild bean understudy will agglutinate and interact with a gram positive bacteria more than gram negative bacteria.

Evaluation of larvicidal efficacy and phytochemical potential of some selected indigenous plant against <i>Anopheles gambiense</i>and <i>Culex quinquefasciatus</i>

Azadirachta indica, Citrus sinensis, Cymbopogon citratus and Annona squamosa were screened and evaluated for their phytochemical composition and larvicidal effects on Anopheles gambiense and Culex quinquefasciatus. The bioassay results showed that the effects were dependent on time and concentration of extract used. Cymbopogon citratus and Citrus sinesis at 20 mg/ml had the highest mortality effect on Anopheles gambiense after 72 h. Citrus sinensis was more effective against Culex quinquefasciatus. Aqueous extracts of these plants were found to have less larvicidal effect against the mosquito vectors. Phytochemical analysis showed the presence of flavonoids in all herbs. Alkaloids were present in Citrus sinensis, Cymbopogon citratus and Annona squamosa while Citrus sinesis and Azadirachta indica were positive for tannins.

Effect of Concentration on the Optical and Solid State Properties of ZnO Thin Films Deposited by Aqueous Chemical Growth (ACG) Method

Thin films of Zinc Oxide (ZnO) having different concentrations were deposited using the Aqueous Chemical Growth (ACG) method. The films were characterized using Rutherford Back Scattering (RBS) spectroscopy for chemical composition and thickness, X-Ray Diffraction (XRD) for crystallographic structure, a UV-VIS spectrophotometer for the analysis of the optical and solid state properties which include spectral absorbance, transmittance, reflectance, refractive index, direct band gap, real and imaginary dielectric constants, absorption and extinction coefficients and a photomicroscope for photomicrographs. The average deposited film thickness was 100 nm. The results indicate that the values of all the optical and solid state properties investigated vary directly with concentration except transmittance which is the reverse. Thus, the optical and solid state properties of ZnO thin film deposited by the Acqueous Chemical Growth method can be tuned by deliberately controlling the concentration of the precursors for various optoelectronic applications including its application as absorber layer in solar cells.