Magnetic Field Enhancement in Ammonia-Water Absorption Refrigeration Systems

Absorption enhancement has been considered as an effective way of improving coefficient of performance (COP) of refrigeration systems and magnetic enhancement is one of these methods. A model of magnetic field enhancement in ammonia-water absorption systems is presented in this paper. A numerical model using finite difference scheme was developed based on the conservation equations and mass transport relationship. Macroscopic magnetic field force was introduced in the momentum equation. The model was validated using data obtained from the literature. Changes in the physical properties of ammonia solution while absorbing both in the direction of falling film and across its thickness were investigated. The magnetic field was found to have some positive effect on the ammonia-water falling film absorption. The results indicate that absorption performance enhancement increased with magnetic intensity. The COP of simple ammonia solution absorption refrigeration system increased by 1.9% and 3.6% for magnetic induction of 1.4 and 3.0 Tesla respectivel

GROWTH PERFORMANCE, NUTRIENT DIGESTIBILITY AND BLOOD INDICES OF FINISHING BROILER CHICKENS FED VARYING LEVELS OF PRE-GELATINIZED CASSAVA GRITS AS A REPLACEMENT FOR MAIZE

Pre gelatinized cassava grit (PGCG) is a new cassava product produced mechanically and commercially for poultry feeding. Five dietary treatments were formulated with PGCG replacing maize at 0, 25, 50, 75 and 100 % in broiler starter (0-4 weeks) and finisher (4-8 weeks) diets. Two hundred (200) day-old broiler chickens were allotted to the five dietary treatments in a completely random design.  Each treatment was replicated four times with 10 birds per replicate and 40 birds per treatment. At the end of week 4 and 8 of the experiment, data were collected on growth performance, nutrient digestibility, haematological and serum biochemical indices. Final weight and weight gain were significantly (P < 0.05) highest in broilers fed 25 % PGCG diet, followed by those fed control diet. While, (P < 0.05) similar and lower values were obtained from broilers fed other PGCG diets. Feed intake decreased (P < 0.05) with PGCG in the diets at the starting and finishing phases. Dry matter and crude protein digestibility was (P < 0.05) highest in starting broilers fed 25 % PGCG diet, while digestibility (P < 0.05) declined with higher levels of PGCG. At the finishing phase, digestibility of all nutrients was similar (P < 0.05). Apparent metabolizable energy was (P < 0.05) higher in birds fed PGCG diets in the starting and finishing phases. Haematological and serum biochemical indices showed no significant (P>0.05) difference in the broiler chickens fed varying levels of PGCG in the diets. Broiler chickens fed PGCG above 25% in the diet had significantly (P < 0.05) higher proventriculus values when compared with those fed the control diet and 25% PGCG diet. The study revealed that substituting maize with 25 % PGCG in broiler diets improved growth and nutrient digestibility. Reduction in weight gain and non significant increased thiocyanate at higher PGCG inclusion should be improved for effective utilization of pre gelatinized cassava grit in broiler diets. &nbsp

DEVELOPMENT AND PERFORMANCE EVALUATION OF A SALT BATH FURNACE

ABSTRACT This research work is centered on the design of a low costefficient salt bath furnace using locally sourced materials for the purpose of carrying out thermochemical treatments of small and minor components for improved properties in service. Working drawings were produced; and mild steel sheet was used for the construction of the furnace casing while other materials for the construction were selected based on functions and properties of the materials, cost considerations and ease of fabrication into component parts. Testing was carried out to evaluate the performance of the furnace. From the results obtained, it was observed that the salt bath furnace has fast heating rate 12.53 0 C/min and a fuel consumption rate of 2.1 litres/hr, which is comparable to rates of conventional brands of diesel fired salt bath and muffle furnaces purchased from abroad. The lower cost of design of the furnace coupled with its good heat retaining capacity, uniform heating rate, long estimated life time, safety and ease of maintenance justifies the usage

Condition-Based Monitoring of Kiln Induced Draft Fan in A Dry Process Cement Plant for Efficient Utilization

Associated downtime and economic loss caused by replacement/maintenance of equipment necessitated pro-active technique known as Condition-Based Monitoring to prevent/reduce failures. This study evaluated the vibration of Kiln Induced Draft (KID) of cement plant before and after failure. Vibration data was acquired using accelerometer probe and data obtained were analyzed statistically by employing t-Test at 95% confidence. Results showed that vibration signals measured in mm/s for KID motor and fan bearings (non-drive and drive ends) in the horizontal plane recorded higher values than vertical and axial planes when measured before failure occurrences. After failures, horizontal plane values increased by more than 120% while those measured in the vertical and axial planes increased by less than 100%, making horizontal plane vibration measurement a more suitable parameter for predicting the machinery health condition. The t-Test conducted showed that mean differences in values of vibration signal data before and after failure are not zero but negatives (signal before failure < signal after failure). Outputs from tests of significance using two-tailed t-Test indicated that the differences in values of vibration data signals are not significant at (p≤ 0.05) when considering “equal variance not assumed”. The non-significance of these mean differences may indicate that the present operational vibration signal level should be maintained at values in order that significant difference may be observed between periods before failure and after failure for efficient prediction of failure, as the present 1.5-3.5 mm/s range is likely not a good range for efficient failure prediction

Point-of-admission hypothermia among high-risk Nigerian newborns

<p>Abstract</p> <p>Background</p> <p>Facilities which manage high-risk babies should frequently assess the burden of hypothermia and strive to reduce the incidence.</p> <p>Objective</p> <p>To determine the incidence and outcome of point-of-admission hypothermia among hospitalized babies.</p> <p>Methods</p> <p>The axillary temperatures of consecutive admissions into a Nigerian Newborn Unit were recorded. Temperature <36.5°C defined hypothermia. The biodata and outcome of these babies were studied.</p> <p>Results</p> <p>Of 150 babies aged 0 to 648 hours, 93 had hypothermia with an incidence of 62%. Mild and moderate hypothermia accounted for 47.3% and 52.7% respectively. The incidence of hypothermia was highest (72.4%) among babies aged less than 24 hours. It was also higher among out-born babies compared to in-born babies (64.4% <it>vs </it>58.3%). Preterm babies had significantly higher incidence of hypothermia (82.5%) compared with 54.5% of term babies (RR = 1.51; CI = 1.21 – 1.89). The incidence of hypothermia was also highest (93.3%) among very-low-birth-weight babies.</p> <p>The Case-Fatality-Rate was significantly higher among hypothermic babies (37.6% vs 16.7%; RR = 2.26, CI = 1.14 – 4.48) and among out-born hypothermic babies (50% vs 17.1%; RR = 0.34, CI = 0.16 – 0.74). CFR was highest among hypothermic babies with severe respiratory distress, sepsis, preterm birth and asphyxia.</p> <p>Conclusion</p> <p>The high incidence and poor outcome of hypothermia among high-risk babies is important. The use of the 'warm chain' and skin-to-skin contact between mother and her infant into routine delivery services in health facilities and at home may be useful.</p

Investigation of livestock for presence of Trypanosoma brucei gambiense in Tafa Local Government Area of Niger State, Nigeria

The study investigated the presence of Trypanosoma brucei gambiense in livestock to ascertain their reservoir role and also screened for other pathogenic trypanosomes of animals in Tafa Local Government Area of Niger state, Nigeria. A total of 460 livestock comprising (cattle, sheep, goats, and dogs) selected at random were bled, examined using the buffy coat and Giemsa stained thin film and packed cell volume estimated. Questionnaire was filled for each animal on demography, awareness and management practices. An overall prevalence of 2.17% with Trypanosoma brucei, T. congolense, T. vivax and a mixed infection of T. brucei and T. congolense observed microscopically awaiting characterization. Interviews revealed high awareness (82.8%) of tsetse and trypanosomiasis described as bush disease and abortion in four cows. The PCV values were within the normal range, however, a significant decrease (P&lt;0.05) was observed in sheep aged 7months to 4years in two communities. Therefore, the study indicated the presence of T. brucei and other trypanosomes suggesting that animal trypanosomiasis is still a problem to animal health and wellbeing in the study area. The study recommends effective integrated chemotherapy and vector control including livestock rearing under intensive management system to boost livestock production and productivity

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Surface-modified polyacrylonitrile nanofibers as supports

Polyacrylonitrile nanofibers (PAN-nfs) are one of the most studied nanofibres because of their excellent characteristics, such as good mechanical strength, chemical resistance, and good thermal stability. Due to the easy dissolution in polar organic solvents, PAN-nfs are mostly produced via electrospinning technique. The electrospun PAN-nfs surfaces are relatively in-active and hydrophobic, and, therefore, hinder some potential applications; however, chemical surface modification reactions, such as amination, reduction, hydrolysis, and amidoximation, have been carried out on them. These reactions bring about functional groups, such as amine, hydroxyl, carboxylic, imine etc, to the surface PAN-nfs and invariably make their surfaces active and hydrophilic. The surface-modified PAN-nfs have been used as supports for organic compounds, enzymes, and antibodies in biological studies. They have also been used for immobilization of various organic ligands for adsorption of metal ions in water. Furthermore, because of their ability to complex metal ions, several surface-modified PAN-nfs have also been used as supports for transition metal catalysts in Fenton’s chemistry.IS

Burden of injury along the development spectrum : associations between the Socio-demographic Index and disability-adjusted life year estimates from the Global Burden of Disease Study 2017

Background The epidemiological transition of non-communicable diseases replacing infectious diseases as the main contributors to disease burden has been well documented in global health literature. Less focus, however, has been given to the relationship between sociodemographic changes and injury. The aim of this study was to examine the association between disability-adjusted life years (DALYs) from injury for 195 countries and territories at different levels along the development spectrum between 1990 and 2017 based on the Global Burden of Disease (GBD) 2017 estimates. Methods Injury mortality was estimated using the GBD mortality database, corrections for garbage coding and CODEm-the cause of death ensemble modelling tool. Morbidity estimation was based on surveys and inpatient and outpatient data sets for 30 cause-of-injury with 47 nature-of-injury categories each. The Socio-demographic Index (SDI) is a composite indicator that includes lagged income per capita, average educational attainment over age 15 years and total fertility rate. Results For many causes of injury, age-standardised DALY rates declined with increasing SDI, although road injury, interpersonal violence and self-harm did not follow this pattern. Particularly for self-harm opposing patterns were observed in regions with similar SDI levels. For road injuries, this effect was less pronounced. Conclusions The overall global pattern is that of declining injury burden with increasing SDI. However, not all injuries follow this pattern, which suggests multiple underlying mechanisms influencing injury DALYs. There is a need for a detailed understanding of these patterns to help to inform national and global efforts to address injury-related health outcomes across the development spectrum.Peer reviewe