Social Entrepreneurship and Sustainable Development

Business entrepreneurship activities in Nigeria has been on the increase, causing changes and boosting economic development to some existent especially in the provision of self employment and earning profit only. But to meet the challenge of sustainable development we require social entrepreneurship which is the application of entrepreneurship attributes of creativity, innovation and motivation combined with the drive to solve the most pressing social problems in the society. The study evaluated the contributions of social entrepreneurship and its core elements in sustainable development using a cross section of entrepreneurs and interest groups from Imo and Abia States. While simple correlation analysis was used to process the data. It was revealed that social entrepreneurship has not contributed effectively to sustainable development due to low level of creativity and innovation in our entrepreneurs Also, this has adversely affected development of women and rural areas. It is therefore recommended that entrepreneurship programmes should not just focus on business – profit and wealth creation but improvement of citizens creativity and innovativeness capability. This will facilitate sustainable development. Keywords: Business entrepreneurship social entrepreneurship, sustainable development creativity, innovation

INVESTIGATION OF CREEP RESPONSES OF SELECTED ENGINEERING MATERIALS

Mechanical Testing, a concept totally ignored previously, is now a major area of concern. Before now, the concept of testing was merely an afterthought of the procurement process. With the advent of science and technology especially of the type seen in our today’s world, the concept of testing is now an integral part of research and development, product design and manufacturing. This work investigated the creep responses of selected engineering materials (Lead, Polypropylene, and Aluminum alloy samples). Procedure for creep testing and analysis of creep properties of engineering materials from test data are reviewed. The experimental results reveal that the creep resistance of PP was the least with a creep rate of 1.66x10-3 min-1 at 33 OC and 14.22 MPa. Typical values of Creep Strain Rates obtained are 23.5x10-3 min-1 for Pb (BS 1178) at 33 OC and 10.34 MPa; and 4.8X10-6 hr-1 for Wrought Al alloy at 200 oC and 54.58 MPa

Comparative Analysis of Chatter Vibration Frequency in CNC Turning of AISI 4340 Alloy Steel with Different Boundary Conditions

In this study, an experimental investigation of chatter vibration frequency in CNC turning of AISI 4340 Alloy Steel material was carried out, with uncoated carbide tool insert (TPG 322) on Fanuc 0i TC CNC lathe machine, with two boundary conditions. The experimental design adopted for this study is the Taguchi parameter design with L9 orthogonal array. Turning tests were carried out on nine samples of the test-piece material for the clamped-free (C-F) condition, and the tests replicated on another set of nine test-pieces for Clamped-Pinned, so-called C-SS workpiece boundary condition.  Chatter vibration frequencies were measured using MXC-1600 digital frequency counter and the frequency plots continuously analysed through DTO 32105 sound signal and frequency analyzer. The main objective is to investigate the process parameters’ performances on the work-piece material of AISI 4340 alloy steel, and to carry out comparisons between the two different boundary conditions vis-à-vis the effects of process parameters which are cutting speed, feed rate and depth of cut on the chatter vibration frequency for the orthogonal turning operation. Chatter vibration frequency values for the C-SS scenario were found to be up to 30% lesser when compared to the C-F machining scenario. Introduction of the tailstock used in pinning the free-end of the slender work-pieces reduced the chances that workpiece would bend; whereas absence of the pinned end means that workpiece may be skewed at an angle in the chuck with increased dynamic deflections at the free end leading to more aggressive workpiece and cutting tool perturbations which are known to favour cutting instability

Plant Waste Hydrolysis by Extracellular Enzymes of Aspergillus niger and Penicillium chrysogenum: Effect of Ammonia Pretreatment

Aspergillus niger (ANL301) and Penicillium chrysogenum (PCL 501) cultured in basal media with cellulose as sole carbon source yielded extracellular enzymes which partially hydrolyzed sawdust and sugarcane pulp into simple sugars. Pre-treatment of sawdust by ammonium hydroxide steeping increased the yield of simple sugars. The reducing sugars released from the pretreated sawdust by the crude enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) were 3.58% and 7.02% of the total hydrolysable sugars respectively. This is in contrast to the 0.92% and 1.02% of the total hydrolysable sugars released respectively by the enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) from the non-pretreated sawdust. Enzymatic hydrolysis of sugarcane pulp by the crude enzymes was not significantly affected by ammonia pre-treatment. Reducing sugars released from non-pretreated sugarcane pulp by the crude enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) were respectively 4.17% and 5.08% of the total hydrolysable sugars

EVALUATION OF CHATTER VIBRATION FREQUENCY IN CNC TURNING OF 4340 ALLOY STEEL MATERIAL

In this study, an experimental investigation of chatter in CNC turning for 4340 Alloy Steel material was carried out. Empirical study of chatter and critical cutting condition in CNC turning has been conducted through a well- designed three-factor three-level experiment, and regression models developed for chatter frequency prediction with up to 99.5% accuracy for the material. The arising model and the mean-effect plots of the cutting speed, feed rate, and depth of cut against Signal-to-Noise (S/N) ratio indicates that increasing feed rates and depth of cuts would bring about increase in chatter vibration frequency while high cutting speeds would have attenuating effects on chatter vibration frequency, thereby suppressing it. The percentage contribution of the cutting parameters to chatter vibration frequency established, and optimal machining condition for the machine chatter optimization obtained at a cutting speed of 320 m/min, feed rate of 0.05mm/rev and depth of cut of 0.5mm. The optimal chatter vibration frequency for the turning tests was found to be 130.00 Hz. With the obtained optimum input parameters for chatter vibration frequency, production operations will be enhanced

Application of High-Voltage, Precision, Low-Power Max9943/Max9944 Operational Amplifier in Industrial Process Control Using ±20ma OR 4-20ma Current-Loop Systems

This article explains how to apply a high-voltage, high-current-drive operational amplifier to convert a voltage signal into a ±20mA or 4–20mA current signal for use in process-control industrial applications. The MAX9943 op amp a family of high-voltage amplifiers that offers precision, low drift, and low power consumption device was used as case study]. Experiments are described and test results presented. Current loops are known for their high immune to noise compare to voltage-modulated signals, a feature that makes it ideal for use in a noisy industrial environment. This signal can travel over a long distance, sending or receiving information from remote locations. A current loop typically includes a sensor, transmitter, receiver, and an ADC or a micro-controller (figure 1). The sensor measures a physical parameters such as pressure or temperature and provides a corresponding output voltage. The transmitter converts the sensor's output into a proportional 4mA-to-20mA current signal, while the receiver then converts the 4mA-to-20mA current into a voltage signal output. This receiver's output is then received, interpreted and converts into a digital signal output by an ADC or a micro-controller. Experiment performed using the relationship the relationship stated in equation 5, shows that if the input voltage level rise above or fall below ±2.5v, the op amp device attains its saturation point and its output voltage can no longer increase. As shown in figure 3, where the curve flatten and no longer follow the ideal linearity characteristics that was supposed

Physiological behavior of newly isolated Bacterium CB1 and Stenotrophomonas maltophilia strain CB2 on Chrysene, Pyrene, Naphthalene and Fluoranthene

The biodegradability of some polycyclic aromatic hydrocarbons were studied in liquid culture media using bacterial strains (Bacterium CB1 and Stenotrophomonas maltophilia strain CB2) isolated from a former industrial site contaminated with organic and inorganic contaminants. The enrichment experiment was done with chrysene. The partial 16S rRNA gene analyses of Bacterium CB-1 possessed 100% similarity to an uncultured bacterium clone nbt020a while Stenotrophomonas maltophilia strain CB2 had 99% similarity to Paenibacillus sp. Y412MC10. Bacterium CB1 and Stenotrophomonas maltophilia strain CB2 degraded naphthalene between the range of 27% and 42%, chrysene 47% and 12%, fluoranthene 5% and 16%, pyrene 12% and 17% respectively. The strains utilized the test compounds as sole source of carbon and energy. As anticipated, the controls (abiotic and killed) losses were insignificant. The residual PAH obtained in some cases correlated to an increase in cell number indicating that our strains were responsible for the degradation

A Study on Sources, Availability and Accessibility of Potable Water in Imo State, Nigeria

Sources, availability and accessibility of potable water were studied in the three geopolitical zones; Okigwe, Owerri, Orlu zones of Imo State, Nigeria. A total of 800 pretested and randomly distributed questionnaires were used on adult respondents in the three zones. Results identified borehole water as the major (65.4%) source of drinking water among the respondents. More than half (53.8%) of the respondents have their water source located less than 50m from their houses, of which 33% have their boreholes located within their compounds. About half of the respondents visit water bodies daily. The highest total rating of supply of water by the respondents was on “poor” supply. The poor rating was more in Okigwe zone where 107 (64.7%) gave poor rating for supply of potable water. The study has shown that although there is availability and accessibility of water, there is need to monitor sitting of water sources and create awareness as well as lay emphasis on purification since what is available and accessible is not potable

Skipping Meals and its Possible Effects on Lipid Profile of Purposively Selected Civil Servants in Aba, Abia State, Nigeria

Skipping meals and its possible effects on lipid profile of purposively selected civil servants in Aba, Abia State, Nigeria was carried out by purposively selecting a total of 35 volunteer human adults. Questionnaires were used to assess the dietary habit while standard biochemical methods were employed for the lipid profile. The results from the anthropometric measurements showed that the mean weights (kg), heights (m), and body mass indices (BMI) (kg/m2) were 80.13 ± 13.41, 1.66 ± 0.18, and 26.98 ± 5.17 respectively for the males and 79.00 ± 16.14, 1.61 ± 0.12, and 26.89 ± 4.78 respectively for the females. The desirable BMI for both males and females are 18.5 to 24.9. Lipid profile result showed that the mean total cholesterol (TCH) was within desirable range of 188.13 ± 45.04 for the males and 196.42 ± 42.39 for the females and the mean high density lipoprotein cholesterol (HDL-C) was within low range of 44.87 ± 10.83 and 43.26±8.58 for the males and the females respectively. However, the mean low density lipoprotein cholesterol (LDL-C) was within the optimal range of 95.56 ± 38.86 and 114.37 ± 30.75 for males and females respectively. The mean triacylglycerols (TG) was within the borderline range of 173.63 ± 113.41 for the males and within normal range of 149.32 ± 100.28 for females. The total cholesterol/ high density lipoprotein ratio (TCHDL ratio) showed that the mean values for males and females were 4.64 ± 1.13 and 4.56 ± 2.02 respectively. The desirable range of TCHDL ratio for both males and females are 3.5 to 6.0. Correlation analysis showed positive correlations between BMI and LDL-C, Waist to hip ratio (WHR) and TAG, Waist circumference (WaistCir) and TAG. The implications of these findings as it relates nutrition and health are discussed

Determinants of Outcome in Febrile Children Admitted into the Emergency Rooms of Two Tertiary Hospitals in Enugu Southeast Nigeria

Introduction: Febrile illnesses have continued to be the highest causes of mortalities in children admitted to the children emergency roomsin Nigeria. This study was carried out to review the determinants of outcome in children admitted for febrile illness into the emergency roomsof two tertiary institutions in Enugu, Nigeria. Materials and Methods: This was a retrospective study of 335 children who presented with fever to the emergency rooms over one year (January–December 2018). Their case records were retrieved, and the necessary information was obtained using a structured questionnaire. Statistical analysis included odds ratio and Chi‑square test. Results: The mean age of the children was 43.20 ± 50.30 months. The mean temperature at presentation was 38.2°C ± 0.9°C. Fever of 39.0°C or above at presentation and fever duration of >2 days were significantly associated with fatal outcome. Children residing in rural areas or referred from other health facilities were more likely to die. The risk of dying from fever was highest when it was associated with diarrhea, weakness, pallor, convulsions, unconsciousness, and difficult/fast breathing. Conclusion: Most of the factors responsible for mortality in febrile children are largely preventable and treatablewhen the presentation is early. Keywords: Determinants, emergency room, febrile children, Nigeria, outcom