IDENTIFICATION AND SOURCES OF MISCONCEPTIONS HELD BY SECONDARY SCHOOL PHYSICS STUDENTS IN HEAT ENERGY IN RIVERS STATE, NIGERIA

The study identified misconceptions held by secondary school students about the concepts of Heat energy and investigated the sources of the misconceptions in Rivers State, Nigeria. A mixed method research design, specifically the descriptive survey and the exploratory analysis, was adopted for the study. The study was guided by two research questions. Using the random sampling technique, a sample of 300 Secondary School 1 (SS 1) Physics students was selected for the study in Ikwerre Local Government Area, Rivers State. Data was collected using three research instruments titled “Heat Energy Performance Test” (r = 0.80), Sources of Misconceptions in Heat Energy Questionnaire” (r = 0.74) and “Misconception in Heat Energy Interview Template”. This study revealed that secondary school students have misconceptions about Heat energy. This study further revealed that teachers' instructional presentation ranked 1st as the source of misconception in the concept of Heat energy, social interactions ranked 2nd, prior knowledge ranked 3rd while textbooks and reference materials ranked 4th. The study thus recommends that Physics teachers should always conduct a diagnostic test before instruction to correct any wrong preconceived notion held by the students about a particular concept before instruction. Also, well-designed and technology-assisted instruction should be adopted by Physics teachers to facilitate an accurate scientific understanding of heat energy.  Article visualizations

CAUSES AND EFFECTS OF PHYSICSPHOBIA AMONG SECONDARY SCHOOL STUDENTS IN RIVERS STATE, NIGERIA: IMPLICATION FOR STUDENTS’ ENROLMENT IN PHYSICS

This study investigated the presence, causes and effects of Physicsphobia among Senior Secondary School physics students in Rivers State. The study had a descriptive survey design. Three research questions guided the study. Purposive random sampling technique was used to select 500 Senior Secondary 1 and 2 (SS1 and SS2) Physics students from forty-four (44) schools in three Local Government Areas of Rivers State, which are Obio-Akpor Local Government Area, Port Harcourt Local Government Area and Gokana Local Government Area. The research instrument was a validated researcher-developed questionnaire titled ‘Students’ Physicsphobia Questionnaire’ with a reliability coefficient of 0.79 obtained using the Cronbach alpha formula. The findings of this study showed that Physicsphobia exists in students. The study further revealed some of the causes of Physicsphobia to be rumors and misleading information about Physics, teaching method, the uninteresting nature of physics lessons, as well as abstract, difficult and mathematical nature of Physics. The study also revealed some of the effects of Physicsphobia in students to be anxiety, rapid heartbeat, frustration, depression and a feeling of leaving Physics class. It was then recommended that conscious effort should be made to paint a better picture of physics, especially for students who are about to start the study of Physics.  Article visualizations

Ordeals of Physics Instruction in Nigerian Secondary Schools: Way Forward for the Attainment of Global Competitiveness

Physics instruction in secondary schools is a fundamental panacea towards achieving scientific knowledgeable citizens which can propel a nation in the realization of a sustainable economic force. This paper therefore x-rayed ordeals of physics instruction in Nigerian secondary schools and the way forward for the attainment of global competitiveness. The research has descriptive survey design. Ninety-two (92) physics teachers and eight secondary schools (four in each Local Government Area) were selected using a purposive sampling technique for the study. The research instruments used for the study were “Questionnaire on Ordeal in Physics Instruction in Secondary School (QOPISS) and Physics Practical Apparatus Checklist (PPAC). Using a test-retest method and Pearson Product Moment Correlation, a reliability coefficient of 0.83 was obtained for QOPISS. The data were analyzed according to research questions using the frequency count, percentage, mean, standard deviation and ranking. The study revealed that qualified physics teachers are not adequate for proper teaching of physics, laboratory apparatus are insufficient for effective practical activities in physics teaching and learning in both rural and urban schools, the lecture and problem solving methods are the most applied instructional strategy employed during physics instruction and physics teachers do not utilize ICT tools in teaching physics. Based on the findings of the study, it was recommended that qualified physics teachers should be employed in the secondary schools, all physics laboratories both in the urban and rural secondary schools should be well equipped by relevant authorities and stake holders, appropriate teaching methodologies and ICT tools integration in the teaching and learning of physics should be employed by physics teachers during physics instruction. Keywords: Physics instruction, laboratory apparatus, physics teachers, ICT tools

The Effect of Electrolyte on Dye Sensitized Solar Cells Using Natural Dye from Mango (M. indica L.) Leaf as Sensitizer

Dye-sensitized solar cells (DSSC) were fabricated with mango leaf dye extracts as natural dye sensitizers at pH value of 5.20 and temperature of 18.1˚C. Methanol was used as dye-extracting solvent. DSSCs from dye extract of M. indica L. with KMnO4 electrolyte had the highest photocurrent density of 1.3 mA/cm2 and fill factor FF of 0.46 for the sun at its peak. Potassium permanganate (KMnO4) had a photocurrent density of 1.3 mA/cm2 and FF of 0.8 at sundown. Potassium Iodide (KI), Potassium Bromide (KBr) and Mercury Chloride (HgCl2) electrolytes had 0.2 mA/cm2, 0.08 mA/cm2 and 0.02 mA/cm2 photocurrent densities respectively. The fill factors of 0.09, 0.03 and 0.003 respectively for sun overhead while 0.08 mA/cm2, 0.01 mA/cm2 and 0.01 mA/cm2 were the values of photocurrent densities respectively at sundown. The fill factors were 0.02, 0.0006 and 0.003 respectively at sundown. The maximum power Pmax of the DSSCs were 0.5 mW/cm2, 0.10 mW/cm2, 0.01 mW/cm2 and 0.012 mW/cm2 respectively at 1300 h at 1630 h 0.9 mW/cm2, 0.14 mW/cm2, 0.005 mW/cm2 and 0.0015 mW/cm2 respectively

Design and Construction of a Pure Sine Wave Inverter

This research is a design and implementation of a sine wave inverter circuit developed to run AC appliances at a low cost which high efficiency. The design consists of two stages i.e. the DC-DC step up stage and a DC-AC Inverter stage. The DC-DC step up converter is based on a push-pull design to step 24VDC to 300VDC. Pulse width modulation was used i.e. the SG3525 pulse width Modulator. The DC-AC inverter stage comprised of four power mosfets in an H-bridge configuration, driven by a 40 kHz square wave encoded/modulated by a 50Hz sine wave that was derived from a TL084 quad op amp sine wave oscillator. An output voltage range of about 240-260VAC from 300VDC input was obtained. A low pass filter was used to filter out the high frequencies and thus isolate the harmonics so a 50 Hz fundamental frequency was retained

Construction of an in-situ smart device that measures some basic environmental factors for agricultural monitoring

Most of the rural agricultural and extension officers have no access to the daily variations in meteorological data that affect the growth and yield of crops. This is as a result of little or no access to the data that could be used to predict the best agricultural practices for optimum output in the rural environments. In this work, a portable and user friendly smart Automated Weather Station (AWS) was constructed. The device that is programmed with Arduino UNO is capable of measuring the temperature, relative humidity and moisture content of the soil. The performance evaluation of the device was observed in the laboratory and onsite (Covenant University farm) both on the sunny and rainy days respectively. It was revealed that there is positive linear relationship between the volume of water added to the soil sample and the soil moisture content in the laboratory measurements. The on-site measurements showed that the temperature is inversely proportional to the relative humidity and soil moisture content. This device is efficient in taking the short-term essential parameters that could improve the yield of agricultural products in the rural environments if properly utilized

Facial Structure Analysis Separates Autism Spectrum Disorders Into Meaningful Clinical Subgroups

Varied cluster analysis were applied to facial surface measurements from 62 prepubertal boys with essential autism to determine whether facial morphology constitutes viable biomarker for delineation of discrete Autism Spectrum Disorders (ASD) subgroups. Earlier study indicated utility of facial morphology for autism subgrouping (Aldridge et al. in Mol Autism 2(1):15, 2011). Geodesic distances between standardized facial landmarks were measured from three-dimensional stereo-photogrammetric images. Subjects were evaluated for autism-related symptoms, neurologic, cognitive, familial, and phenotypic variants. The most compact cluster is clinically characterized by severe ASD, significant cognitive impairment and language regression. This verifies utility of facially-based ASD subtypes and validates Aldridge et al.\u27s severe ASD subgroup, notwithstanding different techniques. It suggests that language regression may define a unique ASD subgroup with potential etiologic differences

Construction of a Mobile Frequency Modulation Transmitter

A Frequency Modulation (FM) transmitter is an electronic device that produces radio waves with the aid of an antenna. The transmitter generates radio frequency alternating current, that is applied to the antenna. When the antenna is excited by the alternating current, the antenna begins to radiate radio waves by varying the frequency of the radio signal. The transmitter is a Very High Frequency (VHF) Colpitts oscillator capable of transmitting sound to standard FM receiver fitted with a capacitor microphone which picks weak sound signals. This design was achieved using: transistors, resistors, inductors and capacitors. A transmission frequency of ± 5% 100 MHz was used and transmitted up to a distance of 5 metres. The testing of the transmitter was carried out by powering it using a 9 V DC battery and tuning a suitable FM receiver to the transmission frequency of the constructed transmitter. A transmission distance of 5 metres was achieved therefore making it possible to use the transmitter as a portable cordless microphone used for public address (P.A.) systems. The achieved fixed frequency of transmission 56.4 MHz, away from all other radio stations transmission frequencies. This gives the best range and with the least of interferences. With increased power, the range can easily be extended